  (This file was generated from ../fetchmail-FAQ.html)
     __________________________________________________________________

                   Frequently Asked Questions About Fetchmail

   Support? Bug reports? Please read G3 for what information is required
   to get your problem solved as quickly as possible.

   Note that this FAQ is occasionally updated from the Git repository and
   speaks in the past tense ("since") about a fetchmail release that is
   not yet available. Please try a release candidate for that version in
   case you need the new option.

   If you have a question or answer you think ought to be added to this
   FAQ list, file it to one of the trackers at our SourceForge.net project
   site or post to one of the fetchmail mailing lists (see below).

                                    Contents

   Detailed Contents
   G. General problems
   B. Build-time problems
   F. Fetchmail configuration file grammar questions
   C. Configuration questions
   T. How to make fetchmail play nice with various MTAs
   S. How to make fetchmail work with various servers
   I. How to fetchmail work with specific ISPs
   K. How to set up well-known security and authentication
   R. Runtime fatal errors
   H. Hangs and lockups
   D. Disappearing mail
   M. Multidrop-mode problems
   X. Mangled mail
   O. Other problems

                               Detailed Contents

General problems

   G1. What is fetchmail and why should I bother?
   G2. Where do I find the latest FAQ and fetchmail sources?
   G3. Something doesn't work/I think I've found a bug. Will you fix it?
   G4. I have this idea for a neat feature. Will you add it?
   G5. I want to make fetchmail remove kept mail after some days.
   G6. Is there a mailing list for exchanging tips?
   G7. So, what's this I hear about a fetchmail paper?
   G8. What is the best server to use with fetchmail?
   G9. What is the best mail program to use with fetchmail?
   G10. How can I avoid sending my password en clair?
   G11. Is any special configuration needed to use a dynamic IP address?
   G12. Is any special configuration needed to use firewalls?
   G13. Is any special configuration needed to send mail?
   G14. Is fetchmail Y2K-compliant?
   G15. Is there a way in fetchmail to support disconnected IMAP mode?
   G16. How will fetchmail perform under heavy loads?

Build-time problems

   [DEL: B1. Make coughs and dies when building on FreeBSD. :DEL]
   B2. Lex bombs out while building the fetchmail lexer.
   B3. I get link failures when I try to build fetchmail.
   B4. I get build failures in the intl directory.

Fetchmail configuration file grammar questions

   F1. Why does my old .fetchmailrc no longer work?
   [DEL: F2. The .fetchmailrc parser won't accept my all-numeric user
   name. :DEL]
   [DEL: F3. The .fetchmailrc parser won't accept my host or username
   beginning with 'no'. :DEL]
   F4. I'm getting a 'parse error' message I don't understand.

Configuration questions

   C1. Why do I need a .fetchmailrc when running as root on my own
   machine?
   C2. How can I arrange for a fetchmail daemon to get killed when I log
   out?
   C3. How do I know what interface and address to use with --interface?
   C4. How can I set up support for sendmail's anti-spam features?
   C5. How can I poll some of my mailboxes more/less often than others?
   C6. Fetchmail works OK started up manually, but not from an init
   script.
   C7. How can I forward mail to another host?
   C8. Why is "NOMAIL" an error?/I frequently get messages from cron!

How to make fetchmail play nice with various MTAs

   T1. How can I use fetchmail with sendmail?
   T2. How can I use fetchmail with qmail?
   T3. How can I use fetchmail with exim?
   T4. How can I use fetchmail with smail?
   T5. How can I use fetchmail with SCO's MMDF?
   T6. How can I use fetchmail with Lotus Notes?
   T7. How can I use fetchmail with Courier IMAP?
   T8. How can I use fetchmail with vbmailshield?

How to make fetchmail work with various servers

   [DEL: S1. How can I use fetchmail with qpopper? :DEL]
   S2. How can I use fetchmail with Microsoft Exchange?
   S3. How can I use fetchmail with HP OpenMail?
   S4. How can I use fetchmail with Novell GroupWise?
   S5. How can I use fetchmail with InterChange?
   S6. How can I use fetchmail with MailMax?
   S7. How can I use fetchmail with FTGate?

How to fetchmail work with specific ISPs

   I1. How can I use fetchmail with Compuserve RPA?
   I2. How can I use fetchmail with Demon Internet's SDPS?
   I3. How can I use fetchmail with usa.net's servers?
   I4. How can I use fetchmail with geocities POP3 servers?
   I5. How can I use fetchmail with Hotmail or Lycos Webmail?
   I6. How can I use fetchmail with MSN?
   I7. How can I use fetchmail with SpryNet?
   I8. How can I use fetchmail with comcast.net or other Maillennium
   servers?
   I9. How can I use fetchmail with GMail/Google Mail?
   I10. How can I use fetchmail with OAUTH2?

How to set up well-known security and authentication methods

   K1. How can I use fetchmail with SOCKS?
   K2. How can I use fetchmail with IPv6 and IPsec?
   K3. How can I get fetchmail to work with ssh?
   K4. What do I have to do to use the IMAP-GSS protocol?
   K5. How can I use fetchmail with SSL or TLS?
   K6. How can I tell fetchmail not to try TLS if the server advertises
   it? Why does fetchmail use STARTTLS, STLS, TLS or SSL even though not
   configured?

Runtime fatal errors

   R1. Fetchmail isn't working, and -v shows 'SMTP connect failed'
   messages.
   R2. When I try to configure an MDA, fetchmail doesn't work.
   R3. Fetchmail dumps core when given an invalid rc file.
   [DEL: R4. Fetchmail dumps core in -V mode, but operates normally
   otherwise. :DEL]
   R5. Running fetchmail in daemon mode doesn't work.
   R6. Fetchmail randomly dies with socket errors.
   R7. Fetchmail running as root stopped working after an OS upgrade
   R8. Fetchmail is timing out after fetching certain messages but before
   deleting them
   R9. Fetchmail is timing out during message fetches
   [DEL: R10. Fetchmail is dying with SIGPIPE. :DEL]
   R11. My server is hanging or emitting errors on CAPA.
   R12. Fetchmail isn't working and reports getaddrinfo errors.
   R13. What does "Interrupted system call" mean?
   R14. Since upgrading fetchmail/OpenSSL, I can no longer connect!
   R15. Help, I'm getting Authorization failure!

Hangs and lockups

   H1. Fetchmail hangs when used with pppd.
   H2. Fetchmail hangs during the MAIL FROM exchange.
   H3. Fetchmail hangs while fetching mail.

Disappearing mail

   D1. I think I've set up fetchmail correctly, but I'm not getting any
   mail.
   D2. All my mail seems to disappear after a dropped connection.
   D3. Mail that was being fetched when I interrupted my fetchmail seems
   to have been vanished.

Multidrop-mode problems

   M0. What about multidrop, anyways?
   M1. I've declared local names, but all my multidrop mail is going to
   root anyway.
   M2. I can't seem to get fetchmail to route to a local domain properly.
   M3. I tried to run a mailing list using multidrop, and I have a mail
   loop!
   [DEL: M4. My multidrop fetchmail seems to be having DNS problems. :DEL]
   M5. I'm seeing long DNS delays before each message is processed.
   M6. How do I get multidrop mode to work with majordomo?
   M7. Multidrop mode isn't parsing envelope addresses from my Received
   headers as it should.
   M8. Users are getting multiple copies of messages.

Mangled mail

   X1. Spurious blank lines are appearing in the headers of fetched mail.
   X2. My mail client can't see a Subject line.
   X3. Messages containing "From" at start of line are being split.
   X4. My mail is being mangled in a new and different way.
   [DEL: X5. Using POP3, retrievals seems to be fetching too much! :DEL]
   X6. My mail attachments are being dropped or mangled.
   X7. Some mail attachments are hanging fetchmail.
   X8. A spurious ) is being appended to my messages.
   X9. Missing "Content-Transfer-Encoding" header with Domino IMAP
   X10. Fetchmail delivers partial messages

Other problems

   O1. The --logfile option doesn't work if the logfile doesn't exist.
   O2. Every time I get a POP or IMAP message the header is dumped to all
   my terminal sessions.
   O3. Does fetchmail reread its rc file every poll cycle?
   O4. Why do deleted messages show up again when I take a line hit while
   downloading?
   O5. Why is fetched mail being logged with my name, not the real From
   address?
   O6. I'm seeing long sendmail delays or hangs near the start of each
   poll cycle.
   O7. Why doesn't fetchmail deliver mail in date-sorted order?
   O8. I'm using pppd. Why isn't my monitor option working?
   O9. Why does fetchmail keep retrieving the same messages over and over?
   [DEL: O10. Why is the received date on all my messages the same? :DEL]
   O11. I keep getting messages that say "Repoll immediately" in my logs.
   O12. Fetchmail no longer expunges mail on a 451 SMTP response.
   O13. I want timestamp information in my fetchmail logs.
   O14. Fetchmail no longer deletes oversized mails with --flush.
   O15. Fetchmail always retains the first message in the mailbox.
   O16. Why is the Fetchmail FAQ only available in ISO-216 A4 format? How
   do I get the FAQ in Letter format?
   O17. Linux logs "TCP(fetchmail:...): Application bug, race in
   MSG_PEEK."
     __________________________________________________________________

                                General problems

G1. What is fetchmail and why should I bother?

   Fetchmail is a one-stop solution to the remote mail retrieval problem
   for Unix machines, quite useful to anyone with an intermittent or
   dynamic-IP connection to a remote mailserver, SLIP or PPP dialup, or
   leased line when SMTP isn't desired. Fetchmail can collect mail using
   any variant of POP or IMAP and forwards to a the local SMTP (via TCP
   socket) or LMTP (via TCP or Unix socket) listener or into an MDA
   program, enabling all the normal forwarding/filtering/aliasing
   mechanisms that would apply to local mail or mail arriving via a
   full-time TCP/IP connection.

   Fetchmail is not a toy or a coder's learning exercise, but an
   industrial-strength tool capable of transparently handling every
   retrieval demand from those of a simple single-user ISP connection up
   to mail retrieval and rerouting for an entire client domain. Fetchmail
   is easy to configure, unobtrusive in operation, powerful, feature-rich,
   and well documented.

   Fetchmail is Open Source Software. The openness of the sources enables
   you to review and customize the code, and contribute your changes.

   A former fetchmail maintainer once claimed that Open Source software
   were the strongest quality assurance, but the current maintainers do
   not believe that open source alone is a criterion for quality – the
   remotely exploitable POP3 vulnerability (CVE-2005-2335) lingered
   undiscovered in fetchmail's code for years, which is a hint that open
   source code does not audit itself.

   Fetchmail is licensed under the GNU General Public License v2. Details,
   including an exception that allows linking against OpenSSL, are in the
   COPYING file in the fetchmail distribution.

   If you found this FAQ in the distribution, see the README for
   fetchmail's full feature list.

G2. Where do I find the latest FAQ and fetchmail sources?

   The latest HTML FAQ is available alongside the latest fetchmail sources
   at the fetchmail home page: http://www.fetchmail.info/. We used to have
   new versions in the iBiblio site, but they have stopped accepting
   uploads, and the fetchmail versions on iBiblio are outdated.

   A text dump of this FAQ is included in the fetchmail distribution.
   Because it freezes at distribution release time, it may not be
   completely current.

   The fetchmail sources are also available in the Git repositories at
   https://gitlab.com/fetchmail/fetchmail and
   https://sourceforge.net/p/fetchmail/git/.

   Note the Git branches:
     * legacy_63 (discontinued, unsupported old branch for 6.3.x releases)
     * legacy_64 (stable 6.4.x releases),
     * legacy_6x (near-future 6.5.x development),
     * next (mid-term future 7.x.x development)

   As of 2020-06-21, there no longer is a master branch. next was renamed
   to old-next, and master was renamed to next.

G3. Something does not work/I think I've found a bug. Will you fix it?

   The first thing you should to is to upgrade to the newest version of
   fetchmail, and then see if the problem reproduces. So you'll probably
   save us both time if you upgrade and test with the latest version
   before sending in a bug report.

   Bugs will be fixed, provided you include enough diagnostic information
   for me to go on. Send bugs to fetchmail-users. When sending bugs or
   asking for help, please do not make up information except your password
   and please report the following:
    1. Your operating system.
    2. Your compiler version, if you built from source; otherwise, the
       name and origin of the RPM or other binary package you installed.
    3. The name and version of the SMTP listener or MDA you are forwarding
       to.
    4. Any command-line options you used.
    5. The output of env LC_ALL=C fetchmail -V called with whatever other
       command-line options you used.
    6. The output of env LC_ALL=C fetchmail --nodetach -vvv --nosyslog
       with whatever other command-line options you use routinely.
       It is very important that the transcript include your POP/IMAP
       server's greeting line, so I can identify it in case of server
       problems. This transcript will not reveal your passwords, which are
       specially masked out precisely so transcripts can be passed around.

   If you have FTP access to your remote mail account, and you have any
   suspicion that the bug was triggered by a particular message, please
   include a copy of the message that triggered the bug.

   If your bug is something that used to work but stopped working when you
   upgraded, then you can help pin the bug down by bisecting, i. e. trying
   intermediate versions of fetchmail until you identify the revision that
   broke your feature. The smart way to do this is by binary search on the
   version sequence. First, try the version halfway between your last good
   one and the current one. If it works, the failure was introduced in the
   upper half of the sequence; if it doesn't, the failure was introduced
   in the lower half. Now bisect that half in the same way. In a very few
   tries, you should be able to identify the exact adjacent pair of
   versions between which your bug was introduced. Please include session
   transcripts (as described in the last bullet point above) of both the
   working and failing versions. Often, the source of the problem can
   instantly identified by looking at the differences in protocol
   transactions.

   It may helpful if you include your .fetchmailrc file, but not necessary
   unless your symptom seems to involve an error in configuration parsing.
   If you do send in your .fetchmailrc, mask the passwords first!
   Otherwise, fetchmail -V – as directed above – will usually suffice.

   If fetchmail seems to run and fetch mail, but the headers look mangled
   (that is, headers are missing or blank lines are inserted in the
   headers) then read the FAQ items in section X before submitting a bug
   report. Pay special attention to the item on diagnosing mail mangling.
   There are lots of ways for other programs in the mail chain to screw up
   that look like fetchmail's fault, but you may be able to fix these by
   tweaking your configuration.

   If the bug involves a core dump or hang, a gdb stack trace is good to
   have. (Bear in mind that you can attach gdb to a running but hung
   process by giving the process ID as a second argument.) You will need
   to reconfigure with:
CFLAGS=-g LDFLAGS=" " ./configure

   Then rebuild in order to generate a version that can be traced with a
   debugger such as gdb, dbx or idb.

   Best of all is a mail file which, when fetched, will reproduce the bug
   under the latest (current) version.

   Any bug I can reproduce will usually get fixed quite quickly. Bugs I
   can't reproduce are a crapshoot. If the solution isn't obvious when I
   first look, it may evade me for a long time (or to put it another way,
   fetchmail is well enough tested that the easy bugs have long since been
   found). So if you want your bug fixed rapidly, it is not just
   sufficient but necessary that you give me a way to easily reproduce it.

G4. I have this idea for a neat feature. Will you add it?

   If it's reasonable for fetchmail and cannot be solved with reasonable
   effort outside of fetchmail, perhaps.

   You can do spam filtering better with procmail or maildrop on the
   server side and (if you're the server sysadmin) sendmail.cf domain
   exclusions. If you really want fetchmail to do it from the client side,
   use a preconnect command to call mailfilter.

   You can do other policy things better with the mda option and script
   wrappers around fetchmail. If it's a prime-time-vs.-non-prime-time
   issue, ask yourself whether a wrapper script called from crontab would
   do the job.

   fetchmail's first job is transport though, and it should do this well.
   If a feature would cause fetchmail to deteriorate in other respects,
   the feature will probably not be added.

   For reasons fetchmail doesn't have other commonly-requested features
   (such as password encryption, or multiple concurrent polls from the
   same instance of fetchmail) see ESR's design notes. Note that this
   document is partially obsoleted by the updated design notes.

G5. I want to make fetchmail remove kept mail after some days.

   The second-most-requested feature for fetchmail, after content-based
   filtering, is the ability to have it remove messages from a maildrop
   after N days, typically to be used with the keep option. Several
   messaging programs with graphical user interface support this feature.

   This feature is not yet implemented. It may be at a future date, spare
   time of developers permitting.

   For the time being, the contrib/ directory contains some unsupported
   tools that may help, namely mold-remover.py and delete-later.

G6. Is there a mailing list for exchanging tips?

   There is a fetchmail-users list <fetchmail-users@lists.sourceforge.net>
   for bug reports and people who want to discuss configuration issues of
   fetchmail. Please see G3 above for information you need to report.

   Then there is a fetchmail-devel list
   <fetchmail-devel@lists.sourceforge.net> for people who want to discuss
   fixes and improvements in fetchmail and help co-develop it.

   Finally, there is also an announcements-only list,
   <fetchmail-announce@lists.sourceforge.net>.

   For all lists, see https://sourceforge.net/p/fetchmail/mailman/ for
   subscription, archive and search links.

G7. So, what's this I hear about a fetchmail paper?

   Eric S. Raymond also considered fetchmail development a sociological
   experiment, an extended test to see if his theory about the critical
   features of the Linux development model was correct.

   He considers the experiment a success. He wrote a paper about it titled
   The Cathedral and the Bazaar which was first presented at Linux
   Kongress '97 in Bavaria and very well received there. It was also given
   at Atlanta Linux Expo, Linux Pro '97 in Warsaw, and the first Perl
   Conference, at UniForum '98, and was the basis of an invited
   presentation at Usenix '98. The folks at Netscape told ESR it helped
   them decide to give away the source for Netscape Communicator.

   If you're reading a non-HTML dump of this FAQ, you can find the paper
   on the Web with a search for that title.

G8. What is the best server to use with fetchmail?

   Fetchmail will work with any POP, IMAP, ETRN, or ODMR server that
   conforms to the relevant standards/RFCs (and even some outright broken
   ones like Microsoft Exchange and Novell GroupWise). This doesn't mean
   it works equally well with all, however. POP2 servers, and POP3 servers
   without UIDL, limit fetchmail's capabilities in various ways described
   on the manual page.

   Most modern Unixes (and effectively all Linux/*BSD systems) come with
   POP3 support preconfigured (but beware of the horribly broken POP3
   server mentioned in D2). An increasing minority also feature IMAP (you
   can detect IMAP support by using the 'Probe for supported protocols'
   function in the fetchmailconf utility - unfortunately it does not
   detect SSL-wrapped variants).

   If you have the option, we recommend using or installing an IMAP4rev1
   or UIDL-capable POP3 server.

   A decent POP3/IMAP server that has recently become popular is Dovecot.

G9. What is the best mail program to use with fetchmail?

   Fetchmail will work with all popular mail transport programs. It also
   doesn't care which user agent you use, and user agents are as a rule
   almost equally indifferent to how mail is delivered into your system
   mailbox. So any of the popular Unix mail agents – elm, alpine (a
   rewrite of pine), nmh (the successor to MH), or mutt – will work fine
   with fetchmail.

   All this having been said, I can't resist putting in a discreet plug
   for mutt. Mutt's interface is only a little different from that of its
   now-moribund ancestor elm, but its flexibility and excellent handling
   of MIME and PGP put it in a class by itself. You won't need its
   built-in POP3 support, though.

G10. How can I avoid sending my password en clair?

   You need to ask whether password encryption alone will really address
   your security exposure. If you think you might be snooped between
   server and client, it's better to use end-to-end encryption such as
   GnuPG (see below) on your whole mail stream so none of it can be read.

   Then, you can use SSL or TLS for complete end-to-end encryption if you
   have a TLS-enabled mailserver.

   One of the advantages of fetchmail over conventional SMTP-push delivery
   is that you may be able to arrange encryption by using ssh(1); see K3.

   Note that ssh is not a complete privacy solution either, as your mail
   could have been snooped in transit to your POP server from wherever it
   originated. For best security, agree with your correspondents to use a
   tool such as GnuPG (Gnu Privacy Guard) or PGP (Pretty Good Privacy).

   If ssh/sshd isn't available, or you find it too complicated for you to
   set up, password encryption will at least keep a malicious cracker from
   deleting your mail, and require him to either tap your connection
   continuously or crack root on the server in order to read it.

   You can deduce what encryptions your mail server has available by
   looking at the server greeting line (and, for IMAP, the response to a
   CAPABILITY query). Do a fetchmail -v to see these, or telnet direct to
   the server port (110 for POP3, 143 for IMAP).

   Your server may have CRAM-MD5 support built in.

   The POP3 facility you are most likely to have available is APOP. This
   is a POP3 feature supported by many servers (fetchmailconf's autoprobe
   facility will detect it and tell you if you have it). If you see
   something in the greeting line that looks like an
   angle-bracket-enclosed Internet address with a numeric left-hand part,
   that's an APOP challenge (it will vary each time you log in). For some
   hosts, you need to register a secret on the host (using popauth(8) or
   some program like that). Specify the secret as your password in your
   .fetchmailrc; it will be used to encrypt the current challenge, and the
   encrypted form will be sent back the the server for verification. Note
   that APOP is no longer considered secure since March 2007.

   Alternatively, you may have Kerberos available. This may require you to
   set up some magic files in your home directory on your client machine,
   but means you can omit specifying any password at all.

   Fetchmail supports two different Kerberos schemes. One is a POP3
   variant called KPOP; consult the documentation of your mail server to
   see if you have it (one clue is the string "krb-IV" in the greeting
   line on port 110). The other is an IMAP and POP3 facility described by
   RFC1731 and RFC1734. You can tell if this one is present by looking for
   AUTH=KERBEROS_V4 in the CAPABILITY response.

   Your POP3 server may have the RFC1938 OTP capability to use one-time
   passwords. To check this, look for the string "otp-" in the greeting
   line. If you see it, and your fetchmail was built with OPIE support
   compiled in (see the distribution INSTALL file), fetchmail will detect
   it also. When using OTP, you will specify a password but it will not be
   sent en clair.

G11. Is any special configuration needed to use a dynamic IP address?

   Yes. In order to avoid giving indigestion to certain picky MTAs
   (notably exim), fetchmail always makes the RCPT TO address it feeds the
   MTA a fully qualified one with a hostname part. Normally it does this
   by appending @ and "localhost", but when you are using Kerberos or ETRN
   mode it will append @ and your machine's fully-qualified domain name
   (FQDN).

   Appending the FQDN can create problems when fetchmail is running in
   daemon mode and outlasts the dynamic IP address assignment your client
   machine had when it started up.

   Since the new IP address (looked up at RCPT TO interpretation time)
   doesn't match the original, the most benign possible result is that
   your MTA thinks it's seeing a relaying attempt and refuses. More
   frequently, fetchmail will try to connect to a nonexistent host address
   and time out. Worst case, you could end up forwarding your mail to the
   wrong machine!

   Use the smtpaddress option to force the appended hostname to one with a
   (fixed) IP address of 127.0.0.1 in your /etc/hosts. (The name
   'localhost' will usually work; or you can use the IP address itself.)

   Only one fetchmail option interacts directly with your IP address,
   'interface'. This option can be used to set the gateway device and
   restrict the IP address range fetchmail will use. Such a restriction is
   sometimes useful for security reasons, especially on multihomed sites.
   See C3.

   I recommend against trying to set up the interface option when
   initially developing your poll configuration – it's never necessary to
   do this just to get a link working. Get the link working first, observe
   the actual address range you see on connections, and add an interface
   option (if you need one) later.

   You can't use ETRN if you have a dynamic IP address (your ISP changes
   your IP address occasionally, possibly with every connect). You need to
   have your own registered domain and a definite IP address registered
   for that domain. The server needs to be configured to accept mail for
   your domain but then queue it to forward to your machine. ETRN just
   tells to server to flush its queue for your domain. Fetchmail doesn't
   actually get the mail in that case.

   You can use On-Demand Mail Relay (ODMR) with a dynamic IP address;
   that's what it was designed for, and it provides capabilities very
   similar to ETRN. Unfortunately ODMR servers are still not yet widely
   deployed, as of 2006.

   If you're using a dynamic-IP configuration, one other (non-fetchmail)
   problem you may run into with outgoing mail is that some sites will
   bounce your email because the hostname you're giving them isn't real
   (and doesn't match what they get doing a reverse DNS on your
   dynamically-assigned IP address). If this happens, you need to hack
   your sendmail so it masquerades as your host. Setting
DMsmarthost.here

   in your sendmail.cf will work, or you can set
MASQUERADE_AS(smarthost.here)

   in the m4 configuration and do a reconfigure. (In both cases, replace
   smarthost.here with the actual name of your mailhost.) See the sendmail
   FAQ for more details.

G12. Is any special configuration needed to use firewalls?

   No. You can use fetchmail with SOCKS, the standard tool for indirecting
   TCP/IP through a firewall. You can find out about SOCKS, and download
   the SOCKS software including server and client code, at the [DEL:
   http://www.socks.nec.com/ :DEL] Link defunct SOCKS distribution site.

   The specific recipe for using fetchmail with a firewall is at K1

G13. Is any special configuration needed to send mail?

   A user asks: but how do we send mail out to the POP3 server? Do I need
   to implement another tool or will fetchmail do this too?

   Fetchmail only handles the receiving side. The sendmail or other
   preinstalled MTA on your client machine will handle sending mail
   automatically; it will ship mail that is submitted while the connection
   is active, and put mail that is submitted while the connection is
   inactive into the outgoing queue.

   Normally, sendmail is also run periodically (every 15 minutes on most
   Linux systems) in a mode that tries to ship all the mail in the
   outgoing queue. If you have set up something like pppd to automatically
   dial out when your kernel is called to open a TCP/IP connection, this
   will ensure that the mail gets out.

G14. Is fetchmail Y2K-compliant?

   Fetchmail is fully Y2K-compliant.

   Fetchmail could theoretically have problems when the 32-bit time_t
   counters roll over in 2038, but I doubt it. Timestamps aren't used for
   anything but log entry generation. Anyway, if you aren't running on a
   64-bit machine by then, you'll deserve to lose.

G15. Is there a way in fetchmail to support disconnected IMAP mode?

   No. Fetchmail is a mail transport agent, best understood as a protocol
   gateway between POP3/IMAP servers and SMTP. Disconnected operation
   requires an elaborate interactive client. It's a very different
   problem.

G16. How will fetchmail perform under heavy loads?

   Fetchmail streams message bodies line-by-line; the most core it ever
   requires per message is enough memory to hold the RFC822 header, and
   that storage is freed when body processing begins. It is, accordingly,
   quite economical in its use of memory. It will store the UID or UIDL
   data in core however, which can become considerable if you are keeping
   lots of messages on the server.

   After startup time, a fetchmail running in daemon mode stats its
   configuration file once per poll cycle to see whether it has changed
   and should be rescanned. Other than that, a fetchmail in normal
   operation doesn't touch the disk at all; that job is left up to the MTA
   or MDA the fetchmail talks to.

   Fetchmail's performance is usually bottlenecked by latency on the POP
   server or (less often) on the TCP/IP link to the server. This is not a
   problem readily solved by tuning fetchmail, or even by buying more
   TCP/IP capacity (which tends to improve bandwidth but not necessarily
   latency).
     __________________________________________________________________

                              Build-time problems

[DEL: B1. Make coughs and dies when building on FreeBSD. :DEL]

   As of release 6.3.0, fetchmail's Makefile[.in] should work flawlessly
   with BSD's portable make used on FreeBSD.

B2. Lex bombs out while building the fetchmail lexer.

   fetchmail 6.3.0 and newer ship with the lexer and parser in .c formats,
   so you do not need to use lex unless you hacked the .l or .y files.

   fetchmail's lexer has been developed with GNU flex and uses some of its
   specialties, so the lexer cannot be compiled with the lex tools shipped
   by some UNIX vendors (HP, SGI, Sun).

B3. I get link failures when I try to build fetchmail.

   If you get errors resembling these:
mxget.o(.text+0x35): undefined referenceto '__res_search'
mxget.o(.text+0x99): undefined reference to '__dn_skipname'
mxget.o(.text+0x11c): undefined reference to '__dn_expand'
mxget.o(.text+0x187): undefined reference to '__dn_expand'
make: *** [fetchmail] Error 1

   then you must add "-lresolv" to the LOADLIBS line in your Makefile once
   you have installed the 'bind' package.

   If you get link errors involving dcgettext, like these:
rcfile_y.o: In function 'yyparse':
rcfile_y.o(.text+0x3aa): undefined reference to 'dcgettext__'
rcfile_y.o(.text+0x4f2): undefined reference to 'dcgettext__'
rcfile_y.o(.text+0x5ee): undefined reference to 'dcgettext__'
rcfile_y.o: In function 'yyerror':
rcfile_y.o(.text+0xc7c): undefined reference to 'dcgettext__'
rcfile_y.o(.text+0xcc8): undefined reference to 'dcgettext__'
rcfile_y.o(.text+0xdf9): more undefined references to 'dcgettext__' follow

   install an up to date version of GNU gettext, reconfigure and rebuild
   fetchmail. If that does not help, reconfigure with '--disable-nls'
   added to the "./configure" command and rebuild.

B4. I get build failures in the intl directory.

   Reconfigure with --disable-nls and recompile.
     __________________________________________________________________

                 Fetchmail configuration file grammar questions

F1. Why does my old .fetchmailrc file no longer work?

  If your file predates 6.4.0

   Note that fetchmail no longer supports SSLv2, and you should avoid
   SSLv3 or TLSv1.0 if possible.

  If your file predates 6.3.0

   The netsec option was discontinued and needs to be removed.

  If your file predates 5.8.9

   If you were using ETRN mode, change your smtphost option to a
   fetchdomains option.

  If your file predates 5.8.3

   The 'via localhost' special case for use with ssh tunnelling is gone.
   Use the %h feature of plugin instead.

  If your file predates 5.6.8

   In 5.6.8, the preauth keyword and option were changed back to auth. The
   preauth synonym will still be supported through a few more point
   releases.

  If your file predates 5.6.5

   The imap-gss, imap-k4, and imap-login protocol types are gone. This is
   a result of a major re-factoring of the authentication machinery;
   fetchmail can now use Kerberos V4 and GSSAPI not just with IMAP but
   with POP3 servers that have RFC1734 support for the AUTH command.

   When trying to identify you to an IMAP or POP mailserver, fetchmail now
   first tries methods that don't require a password (GSSAPI,
   KERBEROS_IV); then it looks for methods that mask your password
   (CRAM-MD5, X-OTP); and only if it the server doesn't support any of
   those will it ship your password en clair.

   Setting the preauth option to any value other than 'password' will
   prevent from looking for a password in your .netrc file or querying for
   it at startup time.

  If your file predates 5.1.0

   In 5.1.0, the auth keyword and option were changed to preauth.

  If your file predates 4.5.5

   If the dns option is on (the default), you may need to make sure that
   any hostname you specify (for mail hosts or for an SMTP target) is a
   canonical fully-qualified hostname). In order to avoid DNS overhead and
   complications, fetchmail no longer tries to derive the fetchmail client
   machine's canonical DNS name at startup.

  If your file predates 4.0.6:

   Just after the 'via' option was introduced, I realized that the
   interactions between the 'via', 'aka', and 'localdomains' options were
   out of control. Their behavior had become complex and confusing, so
   much so that I was no longer sure I understood it myself. Users were
   being unpleasantly surprised.

   Rather than add more options or crock the code, I re-thought it. The
   redesign simplified the code and made the options more orthogonal, but
   may have broken some complex multidrop configurations.

   Any multidrop configurations that depended on the name just after the
   'poll' or 'skip' keyword being still interpreted as a DNS name for
   address-matching purposes, even in the presence of a 'via' option, will
   break.

   It is theoretically possible that other unusual configurations (such as
   those using a non-FQDN poll name to generate Kerberos IV tickets) might
   also break; the old behavior was sufficiently murky that we can't be
   sure. If you think this has happened to you, contact the maintainer.

  If your file predates 3.9.5:

   The 'remote' keyword has been changed to 'folder'. If you try to use
   the old keyword, the parser will utter a warning.

  If your file predates 3.9:

   It could be because you're using a .fetchmailrc that's written in the
   old popclient syntax without an explicit 'username' keyword leading the
   first user entry attached to a server entry.

   This error can be triggered by having a user option such as 'keep' or
   'fetchall' before the first explicit username. For example, if you
   write
poll openmail protocol pop3
    keep user "Hal DeVore" there is hdevore here

   the 'keep' option will generate an entire user entry with the default
   username (the name of fetchmail's invoking user).

   The popclient compatibility syntax was removed in 4.0. It complicated
   the configuration file grammar and confused users.

  If your file predates 2.8:

   The 'interface', 'monitor' and 'batchlimit' options changed after 2.8.

   They used to be global options with 'set' syntax like the batchlimit
   and logfile options. Now they're per-server options, like 'protocol'.

   If you had something like
    set interface = "sl0/10.0.2.15"

   in your .fetchmailrc file, simply delete that line and insert
   'interface sl0/10.0.2.15' in the server options part of your 'defaults'
   declaration.

   Do similarly for any 'monitor' or 'batchlimit' options.

[DEL: F2. The .fetchmailrc parser won't accept my all-numeric user name. :DEL]

   This referred to an older fetchmail 5.x version. Upgrade.

[DEL: F3. The .fetchmailrc parser won't accept my host or username beginning
with 'no'. :DEL]

   This referred to an older fetchmail 5.x version. Upgrade.

F4. I'm getting a 'parse error' message I don't understand.

   The most common cause of mysterious parse errors is putting a server
   option after a user option. Check the manual page; you'll probably find
   that by moving one or more options closer to the 'poll' keyword you can
   eliminate the problem.

   Yes, I know these ordering restrictions are hard to understand.
   Unfortunately, they're necessary in order to allow the 'defaults'
   feature to work.
     __________________________________________________________________

                            Configuration questions

C1. Why do I need a .fetchmailrc when running as root on my own machine?

   Ian T. Zimmerman <itz@rahul.net> asked:

   On the machine where I'm the only real user, I run fetchmail as root
   from a cron job, like this:
    fetchmail -u "itz" -p POP3 -s bolero.rahul.net

   This used to work as is (with no .fetchmailrc file in root's home
   directory) with the last version I had (1.7 or 1.8, I don't remember).
   But with 2.0, it RECPs all mail to the local root user, unless I create
   a .fetchmailrc in root's home directory containing:
     skip bolero.rahul.net proto POP3
          user itz is itz

   It won't work if the second line is just "user itz". This is silly.

   It seems fetchmail decides to RECP the 'default local user' (i.e. the
   uid running fetchmail) unless there are local aliases, and the
   'default' aliases (itz->itz) don't count. They should.

   Answer:

   No they shouldn't. I thought about this for a while, and I don't much
   like the conclusion I reached, but it's unavoidable. The problem is
   that fetchmail has no way to know, in general, that a local user 'itz'
   actually exists.

   "Ah!" you say, "Why doesn't it check the password file to see if the
   remote name matches a local one?" Well, there are two reasons.

   One: it's not always possible. Suppose you have an SMTP host declared
   that's not the machine fetchmail is running on? You lose.

   Two: How do you know server itz and SMTP-host itz are the same person?
   They might not be, and fetchmail shouldn't assume they are unless
   local-itz can explicitly produce credentials to prove it (that is, the
   server-itz password in local-itz's .fetchmailrc file.).

   Once you start running down possible failure modes and thinking about
   ways to tinker with the mapping rules, you'll quickly find that all the
   alternatives to the present default are worse or unacceptably more
   complicated or both.

C2. How can I arrange for a fetchmail daemon to get killed when I log out?

   The easiest way to dispatch fetchmail on logout (which will work
   reliably only if you have just one login going at any time) is to
   arrange for the command 'fetchmail -q' to be called on logout. Under
   bash, you can arrange this by putting 'fetchmail -q' in the file
   '~/.bash_logout'. Most csh variants execute '~/.logout' on logout. For
   other shells, consult your shell manual page.

   Automatic startup/shutdown of fetchmail is a little harder to arrange
   if you may have multiple login sessions going. In the contrib
   subdirectory of the fetchmail distribution there is some shell code you
   can add to your .bash_login and .bash_logout profiles that will
   accomplish this. Thank James Laferriere <babydr@nwrain.net> for it.

   Some people start up and shut down fetchmail using the ppp-up and
   ppp-down scripts of pppd.

C3. How do I know what interface and address to use with --interface?

   This depends a lot on your local networking configuration (and right
   now you can't use it at all except under Linux and the newer BSDs).
   However, here are some important rules of thumb that can help. If they
   don't work, ask your local sysop or your Internet provider.

   First, you may not need to use --interface at all. If your machine only
   ever does SLIP or PPP to one provider, it's almost certainly by a point
   to point modem connection to your provider's local subnet that's pretty
   secure against snooping (unless someone can tap your phone or the
   provider's local subnet!). Under these circumstances, specifying an
   interface address is fairly pointless.

   What the option is really for is sites that use more than one provider.
   Under these circumstances, typically one of your provider IP addresses
   is your mailserver (reachable fairly securely via the modem and
   provider's subnet) but the others might ship your packets (including
   your password) over unknown portions of the general Internet that could
   be vulnerable to snooping. What you'll use --interface for is to make
   sure your password only goes over the one secure link.

   To determine the device:
    1. If you're using a SLIP link, the correct device is probably sl0.
    2. If you're using a PPP link, the correct device is probably ppp0.
    3. If you're using a direct connection over a local network such as an
       ethernet, use the command 'netstat -r' to look at your routing
       table. Try to match your mailserver name to a destination entry; if
       you don't see it in the first column, use the 'default' entry. The
       device name will be in the rightmost column.

   To determine the address and netmask:
    1. If you're talking to slirp, the correct address is probably
       10.0.2.15, with no netmask specified. (It's possible to configure
       slirp to present other addresses, but that's the default.)
    2. If you have a static IP address, run 'ifconfig <device>', where
       <device> is whichever one you've determined. Use the IP address
       given after "inet addr:". That is the IP address for your end of
       the link, and is what you need. You won't need to specify a
       netmask.
    3. If you have a dynamic IP address, your connection IP will vary
       randomly over some given range (that is, some number of the least
       significant bits change from connection to connection). You need to
       declare an address with the variable bits zero and a complementary
       netmask that sets the range.

   To illustrate the rule for dynamic IP addresses, let's suppose you're
   hooked up via SLIP and your IP provider tells you that the dynamic
   address pool is 255 addresses ranging from 205.164.136.1 to
   205.164.136.255. Then
    interface "sl0/205.164.136.0/255.255.255.0"

   would work. To range over any value of the last two octets (65536
   addresses) you would use
    interface "sl0/205.164.0.0/255.255.0.0"

C4. How can I set up support for sendmail's anti-spam features?

   This answer covers versions of sendmail from 8.9.3-20 (the version
   installed in Red Hat 6.2) upwards. If you have an older version,
   upgrade to sendmail 8.9.

   Stock sendmails can now do anti-spam exclusions based on a database of
   filter rules. The human-readable form of the database is at
   /etc/mail/access. The database itself is at /etc/mail/access.db.

   The table itself uses email addresses, domain names, and network
   numbers as keys. For example,
spammer@aol.com         REJECT
cyberspammer.com        REJECT
192.168.212             REJECT

   would refuse mail from spammer@aol.com, any user from cyberspammer.com
   (or any host within the cyberspammer.com domain), and any host on the
   192.168.212.* network. (This feature can be used to do other things as
   well; see the sendmail documentation for details)

   To actually set up the database, run
makemap hash deny <deny

   in /etc/mail.

   To test, send a message to your mailing address from that host and then
   pop off the message with fetchmail, using the -v argument. You can
   monitor the SMTP transaction, and when the FROM address is parsed, if
   sendmail sees that it is an address in spamlist, fetchmail will flush
   and delete it.

   Under no circumstances put your mailhost or any host you accept mail
   from using fetchmail into your reject file. You will lose mail if you
   do this!!!

C5. How can I poll some of my mailboxes more/less often than others?

   Use the interval keyword on the ones that should be checked less often.
   For example, if you do a poll every 5 minutes, and want to poll some
   mailboxes every 5 minutes and some every 30 minutes, use something like
   this:
poll mainsite.example.com  proto pop3 user ....
poll secondary.example.com proto pop3 interval 6 user ...

   Then secondary.example.com will be polled every 6th time that
   mainsite.example.com is polled, which with a polling interval of every
   5 minutes means that secondary.example.com will be polled every 30
   minutes.

C6. Fetchmail works OK started up manually, but not from an init script.

   Often, startup scripts have a different environment than an interactive
   login shell. For instance, $HOME might point to "/root" when you are
   logged in as root, but it might be either unset, or set to "/" when the
   startup scripts are running. That means fetchmail at startup can't find
   the .fetchmailrc.

   Pick a location (such as /etc/fetchmailrc) and use fetchmail's -f
   option to point fetchmail at it. That should solve the problem.

C7. How can I forward mail to another host?

   To forward mail to a host other than the one you are running fetchmail
   on, use the smtphost or smtpname option. See the manual page for
   details.

C8. Why is "NOMAIL" an error?/I frequently get messages from cron!

   Some users want to write scripts that take action only if mail
   could/could not be retrieved, thus fetchmail reports if it has
   retrieved messages or not.

   If you do not want "no mail" to be an error condition (for instance,
   for cron jobs), use a POSIX-compliant shell and add this to the end of
   the fetchmail command line, it will change an exit code of 1 to 0 and
   others to 1:
|| [ $? -eq 1 ]

   If you want to map more than one code to 0, you cannot cascade multiple
   || [ $? -eq N ], but you must instead use the -o operator inside the
   brackets, (see the test(1) manpage for details), such as:
|| [ $? -eq 1 -o $? -eq 9 ]

   A full cron line might then look like this:
*/15 * * * * fetchmail -s || [ $? -eq 1 ]
     __________________________________________________________________

               How to make fetchmail play nice with various MTAs

T1. How can I use fetchmail with sendmail?

   For most sendmails, no special configuration is required. Eric Allman
   tells me that if FEATURE(always_add_domain) is included in sendmail's
   configuration, you can leave the rewrite option off.

   If your sendmail complains "sendmail does not relay", make sure your
   sendmail.cf file says Cwlocalhost so that sendmail recognizes
   'localhost' as a name of its host.

   If you're mailing from another machine on your local network, also
   ensure that its IP address is listed in ip_allow or name in name_allow
   (usually in /etc/mail/)

   If you find that your sendmail doesn't like the address
   'FETCHMAIL-DAEMON@localhost' (which is used in the bouncemail that
   fetchmail generates), you may have to set
   FEATURE(accept_unqualified_senders).

   Günther Leber reports that Digital Unix sendmails won't work with
   fetchmail. The symptom is an error message "553 Local configuration
   error, hostname not recognized as local". The problem is that fetchmail
   normally feeds sendmail with the client machine's host address in the
   MAIL FROM line. These sendmails think this means they're seeing the
   result of a mail loop and suppress the mail. You may be able to work
   around this by running in --invisible mode.

   If you want to support multidrop mode, and you can get access to your
   mailserver's sendmail.cf file, it's a good idea to add this rule:
H?l?Delivered-To: $h

   This will cause the mailserver's sendmail to reliably write the
   appropriate envelope address into each message before fetchmail sees
   it, and tell fetchmail which header it is.  With this change, multidrop
   mode should work reliably even when the Received header omits the
   envelope address (which will typically be the case when the message has
   multiple recipients).  However it will still not distinguish the
   recipients, your only advantage is that no bounce will be sent if a
   message is BCC addressed to multiple users at your site.  To fix even
   that problem, you might want to try the following hack, which is
   however untested and quite experimental:
H?J?Delivered-To: $u

Mmdrop, P=/usr/bin/procmail, F=lsDFMqSPfhnu9J,
    S=EnvFromSMTP/HdrFromSMTP, R=EnvToSMTP/HdrToSMTP,
    T=DNS/RFC822/X-Unix,
    A=procmail -Y -a $u -d $h

   For both hacks, you have to declare 'envelope "Delivered-To:"' on the
   fetchmail side, to put the virtual domain (e.g. 'domain.com') with
   RELAY permission into your access file and to add a line reading
   'domain.com local:local-pop-user' for the first and 'domain.com
   mdrop:local-pop-user' for the second hack to your mailertable.

   You will notice that if the mail already has a Delivered-To header,
   sendmail will not add another.  Further, editing sendmail.cf directly
   is not very comfortable.  Solutions for both problems can be found in
   Peter 'Rattacresh' Backes' 'hybrid' patch against sendmail.  Have a
   look at it, you can find it in the contrib subdirectory.

   Feel free to try Martijn Lievaart's detailed recipe in the contrib
   subdirectory of the fetchmail source distribution, it attempts to
   realize multidrop mailboxes with an external script.

   If for some reason you are invoking sendmail via the mda option (rather
   than delivering to port 25 via smtp), don't forget to include the -i
   switch. Otherwise you will occasionally get mysterious delivery
   failures with a SIGPIPE as the sendmail instance dies. The problem is
   messages with a single dot at start of a text line.

T2. How can I use fetchmail with qmail?

  qmail as your local SMTP server

   Don't! Avoid qmail and netqmail, they are broken and unmaintained.

   Turn on the forcecr option; qmail's listener mode doesn't like header
   or message lines terminated with bare linefeeds.
   (This information contributed by Robert de Bath
   <robert@mayday.cix.co.uk>.)

  qmail as your ISP's POP3 server

   Note that qmail's POP3 server, as of version 1.03 and netqmail 1.05,
   miscalculates the message sizes, so you may see size-related fetchmail
   warnings.

   If a mailhost is using the qmail package, then it is usually possible
   to set up one fetchmail link to reliably collect the mail for an entire
   domain.

   One of the basic features of qmail is the 'Delivered-To:' message
   header. Whenever qmail delivers a message to a local mailbox it puts
   the username and hostname of the envelope recipient on this line. One
   major reason for this is to prevent mail loops, the other is to
   transport envelope information which is essential for multidrop
   (domain-in-a-mailbox) schemes.

   To set up qmail to batch mail for a disconnected site, the ISP-mailhost
   will have normally put that site in its 'virtualhosts' control file so
   it will add a prefix to all mail addresses for this site. This results
   in mail sent to 'username@userhost.userdom.example.com' having a
   'Delivered-To:' line of the form:
       Delivered-To: mbox-userstr-username@userhost.userdom.example.com

   A single host maildrop will be slightly simpler:
       Delivered-To: mbox-userstr-username@userhost.example.com

   The ISP can make the 'mbox-userstr-' prefix anything they choose but a
   string matching the user host name is likely.

   To use this line you must:
    1. Ensure the option 'envelope "Delivered-To"' is in the fetchmail
       config file.
    2. Ensure the option 'qvirtual "mbox-userstr-"' is in the fetchmail
       config file, in order to remove this prefix from the username.
       (added by Luca Olivetti)
    3. Ensure you have a localdomains option containing
       'userdom.example.com' or 'userhost.userdom.example.com'
       respectively.

T3. How can I use fetchmail with exim?

   If you have rewrite on:

   There is an RFC1123 requirement that MAIL FROM and RCPT TO addresses
   you pass to it have to be canonical (e.g. with a fully qualified
   hostname part). Therefore fetchmail tries to pass fully qualified RCPT
   TO addresses. But exim does not by default accept 'localhost' as a
   fully qualified domain. This can be fixed.

   In exim.conf, add 'localhost' to your local_domains declaration if it's
   not already present. For example, the author's site at thyrsus.com
   would have a line reading:
       local_domains = thyrsus.com:localhost

   If you have rewrite off:

   MAIL FROM is a potential problem if the MTAs upstream from your
   fetchmail don't necessarily pass canonicalized From and Return-Path
   addresses, and fetchmail's rewrite option is off. The specific case
   where this has come up involves bounce messages generated by sendmail
   on your mailer host, which have the (un-canonicalized) origin address
   MAILER-DAEMON.

   The right way to fix this is to enable the rewrite option and have
   fetchmail canonicalize From and Return-Path addresses with the
   mailserver hostname before exim sees them. This option is enabled by
   default, so it won't be off unless you turned it off.

   If you must run with rewrite off, there is a switch in exim's
   configuration files that allows it to accept domainless MAIL FROM
   addresses; you will have to flip it by putting the line
        sender_unqualified_hosts = localhost

   in the main section of the exim configuration file. Note that this will
   result in such messages having an incorrect domain name attached to
   their return address (your SMTP listener's hostname rather than that of
   the remote mail server).

T4. How can I use fetchmail with smail?

   Smail 3.2 is very nearly plug-compatible with sendmail, and may work
   fine out of the box.

   We have one report that when processing multiple messages from a single
   fetchmail session, smail sometimes delivers them in an order other than
   received-date order. This can be annoying because it scrambles
   conversational threads. This is not fetchmail's problem, it is an smail
   'feature' and has been reported to the maintainers as a bug.

   Very recent smail versions require an -smtp_hello_verify option in the
   smail config file. This overrides smail's check to see that the HELO
   address is actually that of the client machine, which is never going to
   be the case when fetchmail is in the picture. According to RFC1123 an
   SMTP listener must allow this mismatch, so smail's new behavior
   (introduced sometime between 3.2.0.90 and 3.2.0.95) is a bug.

   You may also need to say -smtp_hello_broken_allow=127.0.0.1 in order
   for smail to accept the "localhost" that fetchmail normally appends to
   recipient addresses.

T5. How can I use fetchmail with SCO's MMDF?

   MMDF itself is difficult to configure, but it turns out that connecting
   fetchmail to MMDF's SMTP channel isn't that hard. You can read an MMDF
   recipe that describes replacing a UUCP link with fetchmail feeding
   MMDF.

T6. How can I use fetchmail with Lotus Notes?

   The Lotus Notes SMTP gateway tries to deduce when it should convert \n
   to \r\n, but its rules are not the intuitive and correct-for-RFC822
   ones. Use 'forcecr'.

T7. How can I use fetchmail with Courier IMAP?

   The courier mta doesn't like RCPT addresses that look like
   someone@localhost. Work around this with an smtphost or smtpaddress.

T8. How can I use fetchmail with vbmailshield?

   vbmailshield's SMTP interpreter is broken. It doesn't understand RSET.

   As a workaround, you can set batchlimit to 1 so RSET is never used.
     __________________________________________________________________

                How to make fetchmail work with various servers

[DEL: S1. How can I use fetchmail with qpopper? :DEL]

   The information that used to be here was obsolete and dropped.

S2. How can I use fetchmail with Microsoft Exchange?

   It's been reliably reported that Exchange 2000's POP3 support is so
   broken that it's unusable. One symptom is that messages without a
   terminating newline get the POP3 message termination dot emitted -- you
   guessed it -- right after the last character of the message, with no
   terminating newline added. This will hang fetchmail or any other
   RFC-compliant server. IMAP is alleged to work OK, though.

   Older versions of Exchange are semi-usable. They randomly drop
   attachments on the floor, though. Microsoft acknowledges this as a
   known bug and apparently has no plans to fix it.

   Fetchmail using IMAP usually supports the proprietary NTLM mode used
   with Microsoft Exchange servers. "Usually" here means that it fails on
   some servers for reasons that we haven't been able to debug yet,
   perhaps it's related to the NTLM domain.

   To enable this NTLM mode, configure fetchmail with the --enable-NTLM
   option and recompile it. Specify a user option value that looks like
   'user@domain': the part to the left of the @ will be passed as the
   username and the part to the right as the NTLM domain.

   Microsoft Exchange violates the POP3 and IMAP RFCs. Its LIST command
   does not reveal the real sizes of mail in the pop mailbox, but the
   sizes of the compressed versions in the exchange mail database (thanks
   to Arjan De Vet and Guido Van Rooij for alerting us to this problem).

   Fetchmail works with Microsoft Exchange, despite this brain damage. Two
   features are compromised. One is that the --limit option will not work
   right (it will check against compressed and not actual sizes). The
   other is that a too-small SIZE argument may be passed to your ESMTP
   listener, assuming you're using one (this should not be a problem
   unless the actual size of the message is above the listener's
   configured length limit).

   ESR learned that there's supposed to be a registry bit that can fix
   this breakage:
HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\MsExchangeIs\Parameters
System\Pop3 Compatibility

   This is a bitmask that controls the variations from the standard
   protocol. The bits defined are:

   0x00000001:
          Report exact message sizes for the LIST command

   0x00000002:
          Allow arbitrary linear whitespace between commands and arguments

   0x00000004:
          Enable the LAST command

   0x00000008:
          Allow an empty PASS command (needed for users with blank
          passwords, but illegal in the protocol)

   0x00000010:
          Relax the length restrictions for arguments to commands
          (protocol requires 40, but some user names may be longer than
          that).

   0x00000020:
          Allow spaces in the argument to the USER command.

   There's another one that may be useful to know about:
KEY_LOCAL_MACHINE\System\CurrentControlSet\Services\MsExchangeIs\Parameters
System\Pop3 Performance

   0x00000001:
          Render messages to a temporary stream instead of sending
          directly from the database (should always be on)

   0x00000002: Flag unrenderable messages (instead of just failing
          commands) (should only be on if you are seeing the problems
          reported in KB Q168109)

   0x00000004:
          Return from the QUIT command before all messages have been
          deleted.

   The Microsoft employee who revealed this information to ESR admitted
   that he couldn't find it anywhere in their public knowledge base.

   Another specific problem we have seen with Exchange servers has as its
   symptom a response to LOGIN that says "NO Ambiguous Alias". Grant
   Edwards writes:

     This means that Exchange Server is too [...] stupid to figure out
     which mailbox belongs to you. Instead of actually keeping track of
     which inbox belongs to which user, it uses some half-witted,
     guess-o-matic heuristic to try to guess your mailbox name from your
     username.

     In your case it doesn't work because your username maps to more than
     one mailbox. For some people it doesn't work because their username
     maps to zero mailboxes.

     You've got several options:
     * Get your administrator to configure the server so that usernames
       and mailbox names are the same.
     * Get your administrator to add an alias that maps your username
       explicitly to your mailbox name.

   But, the best option involves finding a server that runs better
   software.

S3. How can I use fetchmail with HP OpenMail?

   No special configuration is required, but OpenMail versions prior to
   6.0 have an annoying bug similar to the big one in Microsoft Exchange.
   The message sizes it gives in the LIST are rounded to the nearest 1024
   bytes. It also has a nasty habit of discarding headers it doesn't
   recognize, such as X- and Resent- headers.

   OpenMail's project manager claims these bugs have been fixed in 6.0.

   We've had a more recent report (December 2001) that the TOP command
   fails, returning only one line regardless of its argument, on something
   identifying itself as "OpenMail POP3 interface".

S4. How can I use fetchmail with Novell GroupWise?

   The Novell GroupWise IMAP server is (according to the designer of IMAP)
   unusably broken. Among other things, it doesn't include a required
   content length in its BODY[TEXT] response.

   Fetchmail works around this problem to some extent, but no guarantees.

S5. How can I use fetchmail with InterChange?

   You can't. At least not if you want to be able to see attachments.
   InterChange has a bug similar to the MailMax server (see below): it
   reports the message length with attachments but doesn't download them
   on TOP or RETR.

   On Jan 9 2001, the people at InfiniteMail sent ESR mail informing him
   that their new 3.61.08 release of InterChange fixed this problem.

S6. How can I use fetchmail with MailMax?

   You can't. At least not if you want to be able to see attachments.
   MailMax has a bug; it reports the message length with attachments but
   doesn't download them on TOP or RETR.

   Also, we're told that TOP sometimes fails to retrieve the entire
   message even when enough lines have been specified. The MailMax
   developers have acknowledged this bug as of 4 May 2000, but there is no
   fix yet. If you must use this server, force RETR with the fetchall
   option.

S7. How can I use fetchmail with FTGate?

   The FTGate V2 server (and possibly older versions as well) has a weird
   bug. It answers OK twice to a TOP request! Use the fetchall option to
   force use of RETR and work around this bug.
     __________________________________________________________________

                    How to fetchmail work with specific ISPs

I1. How can I use fetchmail with CompuServe RPA?

   First, make sure your fetchmail has the RPA support compiled in. Stock
   fetchmail binaries (such as you might get from an RPM) don't. You can
   check this by looking at the output of fetchmail -V; if you see the
   string "+RPA" after the version ID you're good to go, otherwise you'll
   have to build your own from sources (see the INSTALL file in the source
   distribution for directions).

   Give your CompuServe pass-phrase in lower case as your password. Add
   '@compuserve.com' to your user ID so that it looks like 'user
   <UserID>@compuserve.com', where <UserID> can be either your numerical
   userID or your E-mail nickname. An RPA-enabled fetchmail will
   automatically check for csi.com in the POP server's greeting line. If
   that's found, and your user ID ends with '@compuserve.com', it will
   query the server to see if it is RPA-capable, and if so do an RPA
   transaction rather than a plain-text password handshake.

   Warning: the debug (-v -v) output of fetchmail will show your
   pass-phrase in Unicode!

   These two .fetchmailrc entries show the difference between an RPA and
   non-RPA configuration:
# This version will use RPA
poll csi.com via "pop.site1.csi.com" with proto POP3 and options no dns
    user "CSERVE_USER@compuserve.com" there with password "CSERVE_PASSWORD"
        is LOCAL_USER here options fetchall stripcr

# This version will not use RPA
poll non-rpa.csi.com via "pop.site1.csi.com" with proto POP3 and options no dns
    user "CSERVE_USER" there with password "CSERVE_POP3_PASSWORD"
       is LOCAL_USER here options fetchall stripcr

I2. How can I use fetchmail with Demon Internet's SDPS?

  Single-drop mode

   You can get fetchmail to download the email for just one user from
   Demon Internet's POP3 server by giving it a username consisting of your
   Demon user name followed by your account name, with an at-sign between
   them.

   For example, to download email for the user
   <philh@vision25.demon.co.uk>, you could use the following .fetchmailrc
   file:
set postmaster "philh"
poll pop3.demon.co.uk with protocol POP3:
    user "philh@vision25" is philh

  Multi-drop mode

   Demon Internet's SDPS service is an implementation of POP3. All
   messages have a Received: header added when they enter the maildrop,
   like this:
   Received: from punt-1.mail.demon.net by mailstore for fred@xyz.demon.co.uk
             id 899963657:10:27896:0; Thu, 09 Jul 98 05:54:17 GMT

   To enable multi-drop mode you need to tell fetchmail that 'mailstore'
   is the name of the host which accepted the mail, and let it know the
   hostname part(s) of your E-mail address. The following example assumes
   that your hostname is xyz.demon.co.uk, and that you have also bought
   "mail forwarding" for the domain my-company.co.uk (in which case your
   MTA must also be configured to accept mail sent to
   user@my-company.co.uk)
     poll pop3.demon.co.uk proto pop3 aka mailstore no dns:
       localdomains xyz.demon.co.uk my-company.co.uk
       user xyz is *

   Note that Demon may delete mail on the server which is more than 30
   days old; see their POP3 page for details.

  The SDPS extension

   There's a different way to do multidrop. It's not necessary on Demon
   Internet, since fetchmail can parse Received addresses, but the person
   who implemented this didn't know that. It may be useful if Demon
   Internet ever changes mail transports.

   SDPS includes a non-standard extension for retrieving the envelope of a
   message (*ENV), which fetchmail optionally supports if compiled with
   the --enable-SDPS option. If you have it, the first line of the
   fetchmail -V response will include the string "+SDPS".

   Once you have SDPS compiled in, fetchmail in POP3 mode will
   automatically detect when it's talking to a Demon Internet host in
   multidrop mode, and use the *ENV extension to get an envelope To
   address.

   The autodetection works by looking at the hostname in the POP3 greeting
   line; if you're accessing Demon Internet through a proxy it may fail.
   To force SDPS mode, pick "sdps" as your protocol.

I3. How can I use fetchmail with usa.net's servers?

   Enable 'fetchall'. A user reports that the 2.2 version of USA.NET's POP
   server reports that you must use the 'fetchall' option to make sure
   that all of the mail is retrieved, otherwise some may be left on the
   server. This is almost certainly a server bug.

   The usa.net servers (at least in their 2.2 version, June 1998) don't
   handle the TOP command properly, either. Regardless of the argument you
   give it, they retrieve only about 10 lines of the message. Fetchmail
   normally uses TOP for message retrieval in order to avoid marking
   messages seen, but 'fetchall' forces it to use RETR instead.

   Also, we're told USA.NET adds a ton of hops to your messages. You may
   need to raise the MaxHopCount parameter in your sendmail.cf to avoid
   having fetched mail rejected.

I4. How can I use fetchmail with geocities POP3 servers?

   Nathan Cutler reports that the the mail.geocities.com POP3 servers fail
   to include the first Received line of the message in the send to
   fetchmail. This can solve problems if your MUA interprets Received
   continuations as body lines and doesn't parse any of the following
   headers.

   Workaround is to use "mda" keyword or "--mda" switch:
mda "sed -e '1s/^\t/Received: /' | formail | /usr/bin/procmail -d <user>"

   Replace \t with exactly one tabulation character.

   You should also consider using "fetchall" option because Geocities'
   servers sometimes think that the first 45 messages have already been
   read.

[DEL: I5. How can I use fetchmail with Hotmail or Lycos Webmail? :DEL]

   It appears that both services offer POP3 or IMAP access these days.

   Other than that, it might be possible to use the HotWayDaemon daemon.
   You don't even need to install hotwayd as a daemon in inetd.conf but
   can use it as a plugin. Your configuration should look like this:
poll localhost protocol pop3 tracepolls
   plugin "/usr/local/sbin/hotwayd -l 0 -p yourproxy:yourproxyport"
   username "youremail@hotmail.com" password "yourpassword"
   fetchall

   As a second option you may consider using GetLive, a successor to the
   discontinued Gotmail.

I6. How can I use fetchmail with MSN?

   See I5 above.

I7. How can I use fetchmail with SpryNet?

   SpryNet is no more.

I8. How can I use fetchmail with comcast.net or other Maillennium servers?

   Stock fetchmail will work with a Maillennium POP3/PROXY server... but
   this server will truncate "TOP" responses after 64 - 82 kB (we have
   varying reports), in violation of Internet Standard #53 aka. RFC-1939
   (POP3). Don't mistake this for a fetchmail bug. (Reported July 2003.)
   Comcast documented they haven't understood what this is about in two
   messages from April 2004.

   Beginning with version 6.3.2, fetchmail will fall back to the RETR
   command if the greeting string contains "Maillennium POP3/PROXY
   server", and print a warning message. This means however that fetchmail
   has no means to prevent the "seen" flag from being set on the server
   (Note that officially, POP3 has no notion of seen tracking, but it
   works for some sites.)

   Workaround for older versions: use the fetchall option.

I9. How can I use fetchmail with GMail/Google Mail? and

I10. How can I use fetchmail with OAUTH2?

   You cannot. Use something else. So far the maintainer is only aware of
   abusive OAUTH2 schemes that take end user's freedom of choice away.

   Google and Microsoft have started pushing towards more complex
   authentication schemes based on OAuth 2.0 that require clients and
   users to jump through quite a few hoops, and use web browsers for
   signing in, and software vendors to hand in their software for
   sometimes paid reviews. Such is not going to happen for fetchmail. If
   this hinders access to your account through fetchmail, you may need to
   turn on access for "less secure apps", or create an application or
   service specific password. For Google, this - at some point in time -
   used to live at https://myaccount.google.com/lesssecureapps.
   It is disputable whether an application that does not include web
   browsing capabilities or heavy-weight libraries is "less secure" as
   Google claims.

   Google's IMAP servers, as of April 2008, are broken and re-encode
   MIME-encoded headers improperly and are not feature-complete yet. The
   model how their servers organize mail also deviates in significant ways
   from what the POP3 or IMAP protocol 'fathers' conceived. This means all
   sorts of strange effects, for instance, your sent mail may show up in
   the mail that fetchmail fetches. It's best to avoid fetching mail from
   Google until they are using standards-compliant software.

   If you still need to use Google's mail service, these links may help
   (valid as of 2011-04-13):
     * Other ways to access Gmail > POP
     * Other ways to access Gmail > IMAP
     * Using POP on multiple clients or mobile devices
     * Some [POP3] mail was not downloaded
     * I'm having problems downloading [IMAP] mail
     __________________________________________________________________

          How to set up well-known security and authentication methods

K1. How can I use fetchmail with SOCKS?

   Giuseppe Guerini added a --with-socks compile-time option that supports
   linking with socks library. If you specify the value of this option as
   "yes", the configure script will try to find the Rconnect library and
   set the makefile up to link it. You can also specify a directory
   containing the Rconnect library.

   Alan Schmitt has added a similar --with-socks5 option that may work
   better if you have a recent version of the SOCKS library.

   In either case, fetchmail has no direct configuration hooks, but you
   can specify which socks configuration file the library should read by
   means of the SOCKS_CONF environment variable. In order to bypass the
   SOCKS proxy altogether, you could run (adding your usual options to the
   end of this line):
env SOCKS_CONF=/dev/null fetchmail

K2. How can I use fetchmail with IPv6 and IPsec?

   To use fetchmail with IPv6, you need a system that supports IPv6, the
   "Basic Socket Interface Extensions for IPv6" (RFC 2133).

   The NRL IPv6+IPsec software distribution can be obtained from:
   http://web.mit.edu/network/isakmp/

   More information on using IPv6 with Linux can be obtained from:
     * http://www.bieringer.de/linux/IPv6/IPv6-HOWTO/IPv6-HOWTO.html

K3. How can I get fetchmail to work with ssh?

   Use the plugin option. This is dead simple with IMAP:
    plugin "ssh %h /usr/sbin/imapd"

   You may have to use a different absolute pathname, whatever the
   location of imapd on your mailserver is. This option tells fetchmail
   that instead of opening a connection on the server's port 143 and doing
   standard IMAP authentication, fetchmail should ssh to the server and
   run imapd, using the more secure ssh authentication (as well as getting
   ssh's end-to-end encryption). Most IMAP daemons will detect that
   they've been called from the command line and assume the connection is
   preauthenticated.

   POP3 daemons aren't quite as smart. They won't know they are
   preauthenticated in this mode, so you'll actually have to ship your
   password. It will be under ssh encryption, though, so that shouldn't be
   a problem.

K4. What do I have to do to use the IMAP-GSS protocol?

   Fetchmail can use RFC1731 GSSAPI authorization to safely identify you
   to your IMAP server, as long as you can share Kerberos V credentials
   with your mail host and you have a GSSAPI-capable IMAP server.

   fetchmail does not compile in support for GSS by default, since it
   requires libraries from a Kerberos V distribution, such as MIT Kerberos
   or Heimdal Kerberos.

   If you have these, compiling in GSS support is simple: add a
   --with-gssapi=[/path/to/krb5/root] option to configure. For instance, I
   have all of my Kerberos V libraries installed under /usr/krb5 so I run
   configure --with-gssapi=/usr/krb5

   Setting up Kerberos V authentication is beyond the scope of this FAQ
   (you may find Jim Rome's paper How to Kerberize your site helpful), but
   you'll at least need to add a credential for imap/[mailhost] to the
   keytab of the mail server (IMAP doesn't just use the host key). Then
   you'll need to have your credentials ready on your machine (cf. kinit).

   After that things are very simple. Set your protocol to imap-gss in
   your .fetchmailrc, and omit the password, since imap-gss doesn't need
   one. You can specify a username if you want, but this is only useful if
   your mailbox belongs to a username different from your Kerberos
   principal.

   Now you don't have to worry about your password appearing in cleartext
   in your .fetchmailrc, or across the network.

K5. How can I use fetchmail with SSL or TLS?

   You'll need to have the OpenSSL or wolfSSL libraries installed. See the
   relevant README.SSL file that shipped with your fetchmail for the exact
   versions needed. Configure with --with-ssl (default since fetchmail
   v6.4.0). If you have the OpenSSL libraries installed in commonly-used
   default locations, or the library comes with a pkg-config compatible
   .pc file on your system, this will often suffice. If you have them
   installed in a non-default location, you'll need to specify the OpenSSL
   installation directory as an argument to --with-ssl after an equal
   sign.

   Fetchmail binaries built this way support ssl and tls, sslkey, and
   sslcert options that control SSL encryption, and will automatically try
   to negotiate starttls or stlsif the server offers it. You will need to
   have an SSL/TLS-enabled mailserver to use these options. See the manual
   page for details and some words of care on the limited security
   provided.

   If your open OpenSSL session dies with a message that complains "PRNG
   not seeded", update or improve your operating system. This means that
   the OpenSSL library on your machine has been unable to locate a source
   of random bits from which to seed its random-number generator; normally
   these come from the /dev/urandom, and this message probably means your
   OS doesn't have that device.

   An interactive program could seed the random number generator from
   keystroke timings or some other form of user input. Because fetchmail
   is primarily designed to run forever as a background daemon, that
   option is not available in this case.

   If you don't have the libraries installed, but do have the OpenSSL
   utility toolkit, something like this may work (but will not
   authenticate the server):
poll MYSERVER port 993 plugin "openssl s_client -connect %h:%p"
        protocol imap username MYUSERNAME password MYPASSWORD

   You should note that SSL or TLS are only secure against a
   "man-in-the-middle" attack if the client is able to verify that the
   presented peer's public key is the correct one, and has not been
   substituted by an attacker along the way. fetchmail can do this in one
   of two ways: by verifying the SSL certificate, or by checking the
   fingerprint of the peer's public key.

   There are three parts to TLS certificate verification: checking that
   the domain name in the certificate matches the hostname you asked to
   connect to; checking that the certificate expiry date has not passed;
   and checking that the certificate has been signed by a known
   Certificate Authority (CA). This last step takes some preparation, as
   you need to install the root certificates of all the CA's which you
   might come across.

   The easiest way to do this is using the root CA keys supplied in the
   OpenSSL distribution, which means you need to download and unpack the
   source tarball from www.openssl.org. Once you have done that:
    1. mkdir /etc/ssl/certs
    2. in the openssl-x.x.x/certs directory: cp *.pem /etc/ssl/certs/
    3. in the openssl-x.x.x/tools directory: edit c_rehash and set
       $dir="/etc/ssl"
    4. run "perl c_rehash". This generates a number of symlinks within the
       /etc/ssl/certs/ directory

   Now in .fetchmailrc, set option sslcertpath to point to this directory:
poll pop3.example.com proto pop3 uidl no dns
  user foobar@example.com password xyzzy is foobar ssl sslcertpath /etc/ssl/cert
s

   If the server certificate has not been signed by a known CA (e.g. it is
   a self-signed certificate), then this certificate validation will
   always fail.

   Certificate verification is always attempted. If it fails, since
   v6.4.0, by default the connection aborts (6.3 and older would carry on
   after printing a warning, unless --sslcertck was in effect). If your
   server doesn't have a valid certificate though (e.g. it has a
   self-signed certificate) then it will never verify, and the only way
   you can protect yourself is by checking the fingerprint. You should
   then contact the operator and as for properly issued certificates.

   To check the peer fingerprint: first use fetchmail -v once to connect
   to the host, at a time when you are pretty sure that there is no attack
   in progress (e.g. you are not traversing any untrusted network to reach
   the server). Make a note of the fingerprint shown. Now embed this in
   your .fetchmailrc using the sslfingerprint option: e.g.
poll pop3.example.com proto pop3 uidl no dns
  user foobar@example.com password xyzzy is foobar
  ssl sslfingerprint "67:3E:02:94:D3:5B:C3:16:86:71:37:01:B1:3B:BC:E2"

   When you next connect, the public key presented by the server will be
   verified against the fingerprint given. If it's different, it may mean
   that a man-in-the-middle attack is in progress - or it might just mean
   that the server changed its key. It's up to you to determine which has
   happened.

K6. How can I tell fetchmail not to use TLS if the server advertises it? Why
does fetchmail use STARTTLS, STLS, TLS or SSL even though not configured?

   Some options in fetchmail - including sslcertck that has become the
   default in v6.4.0 - require fetchmail to negotiate SSL or TLS. In other
   situations, fetchmail tries to negotiate SSL or TLS opportunistically:
   Some servers advertise STLS (POP3) or STARTTLS (IMAP), and fetchmail
   will automatically attempt TLS negotiation if SSL was enabled at
   compile time. This can however cause problems if the upstream didn't
   configure his certificates properly.

   In some situations, the server does not offer STARTTLS or STLS, but it
   would offer a TLS-wrapped operation on a dedicated, separate port. In
   such a situation, adding ssl to the rcfile (or --ssl on the command
   line) is all there is to it. Fetchmail will use the default port for
   the "secure" service and negotiate TLS or SSL right away.

   In order to prevent fetchmail 6.4.0 and newer versions from trying STLS
   or STARTTLS negotiation, and only as a last resort because it exposes
   all communication to potential eavesdroppers, you could add this
   option:
sslproto ''
     __________________________________________________________________

                              Runtime fatal errors

R1. Fetchmail isn't working, and -v shows 'SMTP connect failed' messages.

   Fetchmail itself is probably working, but your SMTP port 25 listener is
   down or inaccessible.

   The first thing to check is if you can telnet to port 25 on your smtp
   host (which is normally 'localhost' unless you've specified an smtp
   option in your .fetchmailrc or on the command line) and get a greeting
   line from the listener. If the SMTP host is inaccessible or the
   listener is down, fix that first.

   In Red Hat Linux 6.x, SMTP is disabled by default. To fix this, set
   "DAEMON=yes" in your /etc/sysconfig/sendmail file, then restart
   sendmail by running "/sbin/service sendmail restart".

   If the listener seems to be up when you test with telnet, the most
   benign and typical problem is that the listener had a momentary seizure
   due to resource exhaustion while fetchmail was polling it -- process
   table full or some other problem that stopped the listener process from
   forking. If your SMTP host is not 'localhost' or something else in
   /etc/hosts, the fetchmail glitch could also have been caused by
   transient nameserver failure.

   Try running fetchmail -v again; if it succeeds, you had one of these
   kinds of transient glitch. You can ignore these hiccups, because a
   future fetchmail run will get the mail through.

   If the listener tests up, but you have chronic failures trying to
   connect to it anyway, your problem is more serious. One way to work
   around chronic SMTP connect problems is to use --mda. But this only
   attacks the symptom; you may have a DNS or TCP routing problem. You
   should really try to figure out what's going on underneath before it
   bites you some other way.

   We have one report (from toby@eskimo.com) that you can sometimes solve
   such problems by doing an smtp declaration with an IP address that your
   routing table maps to something other than the loopback device (he used
   ppp0).

   We also have a report that this error can be caused by having an
   /etc/hosts file that associates your client host name with more than
   one IP address.

   It's also possible that your DNS configuration isn't looking at
   /etc/hosts at all. If you're using libc5, look at /etc/resolv.conf; it
   should say something like:
        order hosts,bind

   so your /etc/hosts file is checked first. If you're running GNU libc6,
   check your /etc/nsswitch.conf file. Make sure it says something like
        hosts:  files dns

   again, in order to make sure /etc/hosts is seen first.

   If you have a hostname set for your machine, and this hostname does not
   appear in /etc/hosts, you will be able to telnet to port 25 and even
   send a mail with rcpt to: user@host-not-in-/etc/hosts, but fetchmail
   can't seem to get in touch with sendmail, no matter what you set
   smtpaddress to.

   We had another report from a Linux user of fetchmail 2.1 who solved his
   SMTP connection problem by removing the reference to -lresolv from his
   link line and relinking. Apparently in some older Linux distributions
   the libc bind library version works better.

   As of 2.2, the configure script has been hacked so the bind library is
   linked only if it is actually needed. So under Linux it won't be, and
   this particular cause should go away.

R2. When I try to configure an MDA, fetchmail doesn't work.

   (I hear this one from people who have run into the blank-line problem
   in X1.)

   Try sending yourself test mail and retrieving it using the command-line
   options '-k -m cat'. This will dump exactly what fetchmail retrieves to
   standard output (plus the Received line fetchmail itself adds to the
   headers).

   If the dump doesn't match what shows up in your mailbox when you
   configure an MDA, your MDA is mangling the message. If it doesn't match
   what you sent, then fetchmail or something on the server is broken.

R3. Fetchmail dumps core when given an invalid rc file.

   Note that this bug should no longer occur when using prepackaged
   fetchmail versions or installing unmodified original tarballs, since
   these ship with a proper parser .c file.

   This is usually reported from AIX or Ultrix, but has even been known to
   happen on Linuxes without a recent version of flex installed. The
   problem appears to be a result of building with an archaic version of
   lex.

   Workaround: fix the syntax of your .fetchmailrc file.

   Fix: build and install the latest version of flex.

[DEL: R4. Fetchmail dumps core in -V mode, but operates normally otherwise.
:DEL]

   The information that used to be here referred to bugs in Linux libc5
   systems, which are deemed obsolete by now.

R5. Running fetchmail in daemon mode doesn't work.

   We have one report from a SunOS 4.1.4 user that trying to run fetchmail
   in detached daemon mode doesn't work, but that using the same options
   with -N (nodetach) is OK. We have another report of similar behavior
   from one Linux user, but many other Linux users report no problem.

   If this happens, you have a specific portability problem with the code
   in daemon.c that detaches and backgrounds the daemon fetchmail. The
   isolated Linux case has been chased down to a failure in dup(2) that
   may reflect a glibc bug.

   As a workaround, you can start fetchmail with -N and an ampersand to
   background it. A Sun user recommends this:
(fetchmail --nodetach <other params> &)

   The extra pair of parens is significant --- it makes sure that the
   process detaches from the initial shell (one more shell is started and
   dies immediately, detaching fetchmail and making it child of PID 1).
   This is important when you start fetchmail interactively and than quit
   interactive shell. The line above makes sure fetchmail lives after
   that!

R6. Fetchmail randomly dies with socket errors.

   Check the MTU value in your PPP interface reported by /sbin/ifconfig.
   If it's over 600, change it in your PPP options file. (/etc/ppp/options
   on my box). Here are option values that work:
  mtu 552
  mru 552

   Another circumstance that can trigger this is if you are polling a
   virtual-mail-server name that is round-robin connected to different
   actual servers, so you get different IP addresses on different poll
   cycles. To work around this, change the poll name either to the real
   name of one of the servers in the ring or to a corresponding IP
   address.

R7. Fetchmail running as root stopped working after an OS upgrade

   In RH 6.0, the HOME value in the boot-time root environment changed
   from /root to / as the result of a change in init. Move your
   .fetchmailrc or use a -f option to explicitly point at the file.
   (Oddly, a similar problem has been reported from Debian systems.)

R8. Fetchmail is timing out after fetching certain messages but before deleting
them

   There's a TCP/IP stalling problem under Redhat Linux 6.0 that can cause
   this symptom. Brian Boutel writes:

     TCP timestamps are turned on on my Linux boxes (I assume it's now
     the default). This uses 12 extra bytes per segment. When the tcp
     connection starts, the other end agrees a MSS of 1460, and then
     fragments 1460 byte chunks into 1448 and 12, because is is not
     allowing for the timestamp.

     Then, for reasons I can't explain, it waits a long time (typically 2
     minutes) after the ack is sent before sending the next (fragmented)
     packet. Turning off tcp timestamps avoids the fragmentation and
     restores normal behaviour. To do this, [execute]

     echo 0 > /proc/sys/net/ipv4/tcp_timestamps

     I'm still unclear about the details of why this is happening. At
     least [now] I am now getting good performance and no queue blocking.

R9. Fetchmail is timing out during message fetches

   This is probably a general networking issue. Sending a "RETR" command
   will cause the server to start sending large amounts of data, which
   means large packets. If your networking layer has a
   packet-fragmentation problem or improper firewall settings break Path
   MTU discovery (when for instance all ICMP traffic is blocked), that's
   where you'll see it.

[DEL: R10. Fetchmail is dying with SIGPIPE. :DEL]

   Fetchmail 6.3.5 and newer block SIGPIPE, and many older versions have
   already handled this signal, so you shouldn't be seeing SIGPIPE at all.

R11. My server is hanging or emitting errors on CAPA.

   Your POP3 server is broken. You can work around this with the
   declaration auth password in your .fetchmailrc.

R12. Fetchmail isn't working and reports getaddrinfo errors.

    1. Make sure you haven't mistyped the host name or address, and that
       your DNS is working. If you cannot fix DNS, give the numeric host
       literal, for instance, 192.168.0.1
    2. Make sure your /etc/services file (or other services database)
       contains the necessary service entries. If you cannot fix the
       services database, use the --service option and give the numeric
       port address. Common port addresses are:

       service  port
       IMAP     143
       IMAP+SSL 993
       POP3     110
       POP3+SSL 995

R13. What does "Interrupted system call" mean?

   Non-fatal signals (such as timers set by fetchmail itself) can
   interrupt long-running functions and will then be reported as
   "Interrupted system call". These can sometimes be timeouts.

R14. Since upgrading fetchmail/OpenSSL, I can no longer connect!

   If the upgrade you did encompassed an upgrade to OpenSSL 1.0.0 or
   newer, you may need to run c_rehash on your certificate directories,
   particularly if you are using local certs directories (f. i. through
   fetchmail's --sslcertpath option).

   Reason: OpenSSL 1.0.0, relative to earlier versions, uses a different
   hash for the symbolic links (symlinks) in its certs/ directory, so you
   need to recreate the symlinks by running c_rehash /etc/ssl/certs
   (adjust this to where your installation keeps its certificates), and
   you cannot easily share this certs directory with applications linked
   against older OpenSSL versions.

   Note: OpenSSL's c_rehash script is broken in several versions, which
   can cause malfunction if several OpenSSL tools versions are installed
   in parallel in separate directories. In such cases, you may need a
   workaround to get things going. Assuming your OpenSSL 3.0 is installed
   in /opt/openssl3.0 and your certificates are in /home/hans/certs, you'd
   do this (the corresponding fetchmail option is --sslcertpath
   /home/hans/certs on the commandline and sslcertpath /home/hans/cert in
   the rcfile):
env PATH=/opt/openssl3.0/bin /opt/openssl3.0/bin/c_rehash /home/hans/certs

R15. Help, I'm getting Authorization failure!

   First, try upgrading to fetchmail 6.3.18 or newer. Release 6.3.18 has
   received a considerable number of bug fixes for the authentication
   feature (AUTH, AUTHENTICATE, SASL). Most notably, fetchmail aborts SASL
   authentication attempts properly with an asterisk if it detects that it
   cannot make progress with a particular authentication scheme. This
   fixes issues where GSSAPI-enabled fetchmail cannot authenticate against
   Microsoft Exchange 2007 and 2010. Note that this is a bug in old
   fetchmail versions!

   Fetchmail by default attempts to authenticate using various schemes.
   Fetchmail tries these schemes in order of descending security, meaning
   the most secure schemes are tried first.

   However, sometimes the server offers a secure authentication scheme
   that is not properly configured, or an authentication scheme such as
   GSSAPI that requires credentials to be acquired externally. In some
   situations, fetchmail cannot know that the scheme will fail beforehand,
   without trying it. In most cases, fetchmail should proceed to the next
   authentication scheme automatically, but this sometimes does not work.

   Solution: Configure the right authentication scheme explicitly, for
   instance, with --auth cram-md5 or --auth password on the command line
   or auth "cram-md5" or auth "password" in the rcfile. Details can be
   found in the manual page.
   Note that auth password should only be used across secure links (see
   the sslcertck and ssl/sslproto options).
     __________________________________________________________________

                               Hangs and lockups

H1. Fetchmail hangs when used with pppd.

   Your problem may be with pppd's 'demand' option. We have a report that
   fetchmail doesn't play well with it, but works with pppd if 'demand' is
   turned off. We have no idea why this is.

H2. Fetchmail hangs during the MAIL FROM exchange.

   The symptom: 'fetchmail -v' retrieves mail fine, but appears to hang
   after sending the MAIL FROM command
SMTP> MAIL FROM: <someone@somewhere>

   The hang is actually occuring when sendmail looks up a sender's address
   in DNS. The problem isn't in fetchmail but in the configuration of
   sendmail. You must enable the 'nodns' and 'nocanonify' features of
   sendmail.

   Here was my fix for RedHat 7.2:
    1. # cd /etc/mail
    2. # cp sendmail.mc sendmail-mine.mc
    3. Edit sendmail-mine.mc and add lines:
   FEATURE(nodns)
   FEATURE(nocanonify)

    4. Build a new sendmail.cf
   # m4 sendmail-mine.cf > /etc/sendmail.cf

    5. Restart sendmail.

   For more details consult the file /usr/share/sendmail-cf/README.

H3. Fetchmail hangs while fetching mail.

   Symptom: 'fetchmail -v' retrieves the first few messages, but hangs
   returning:
 fetchmail: SMTP< 550 5.0.0 Access denied
 fetchmail: SMTP> RSET
 fetchmail: SMTP< 250 2.0.0 Reset state
 .......fetchmail:  flushed
 fetchmail: POP3> DELE 1
 fetchmail: POP3< +OK marked deleted

   Check and see if you're allowing sendmail connections through TCP
   wrappers.

   Adding 'sendmail : 127.0.0.1' to /etc/hosts.allow could solve this
   problem.
     __________________________________________________________________

                               Disappearing mail

D1. I think I've set up fetchmail correctly, but I'm not getting any mail.

   Maybe you have a .forward or alias set up that you've forgotten about.
   You should probably remove it.

   Or maybe you're trying to run fetchmail in multidrop mode as root
   without a .fetchmailrc file. This doesn't do what you think it should;
   see question C1.

   Or you may not be connecting to the SMTP listener. Run fetchmail -v and
   see R1.

   Or you may have your local user set incorrectly. In the following line
        user 'remoteuser' there with password '*' is 'localuser' here

   make sure that 'localuser' does exist and can receive mail.

D2. All my mail seems to disappear after a dropped connection.

   One POP3 daemon used in the Berkeley Unix world that reports itself as
   POP3 version 1.004 actually throws the queue away. 1.005 fixed that. If
   you're running this one, upgrade immediately. (It also truncates long
   lines at column 1024.)

   Many POP servers, if an interruption occurs, will restore the whole
   mail queue after about 10 minutes. Better ones will restore it right
   away. If you have an interruption and don't see it right away, cross
   your fingers and wait ten minutes before retrying.

   Good servers are designed to restore the entire queue, including
   messages you have deleted. If you have one of these and it flakes out
   on you a lot, try setting a small --fetchlimit value. This will result
   in more IP connects to the server, but will mean it actually executes
   changes to the queue more often.

D3. Mail that was being fetched when I interrupted my fetchmail seems to have
been vanished.

   Fetchmail only sends a delete mail request to the server when either
   (a) it gets a positive delivery acknowledgment from the SMTP listener,
   or (b) it gets one of the spam-filter errors (see the description of
   the antispam> option) from the listener. No interrupt can cause it to
   lose mail.

   However, IMAP2bis has a design problem in that its normal fetch command
   marks a message 'seen' as soon as the fetch command to get it is sent
   down. If for some reason the message isn't actually delivered (you take
   a line hit during the download, or your port 25 listener can't find
   enough free disk space, or you interrupt the delivery in mid-message)
   that 'seen' message can lurk invisibly in your server mailbox forever.

   Workaround: add the 'fetchall' keyword to your fetch options.

   Solution: switch to an IMAP4 server.
     __________________________________________________________________

                            Multidrop-mode problems

M0. What about multidrop, anyways?

   Multidrop is a way to receive mail for several receivers in one
   mailbox. It is sort of abusing the system (using address extensions
   would be more useful, where available) and has quite some requirements
   to work properly. I wrote a separate article to document this, it is
   avavailable in English and in German.

M1. I've declared local names, but all my multidrop mail is going to root
anyway.

   Somehow your fetchmail is never recognizing the hostname part of
   recipient names it parses out of Envelope-header lines (or these are
   improperly configured) as matching a name within the designated
   domains. To check this, run fetchmail in foreground with -v -v on. You
   will probably see a lot of messages with the format "line rejected, %s
   is not an alias of the mailserver" or "no address matches; forwarding
   to %s."

   These errors usually indicate some kind of configuration problem.

   The easiest workaround is to add a 'via' option (if necessary) and add
   enough 'aka' declarations to cover all of your mailserver's aliases,
   then say 'no dns'. This will take DNS out of the picture (though it
   means mail may be uncollected if it's sent to an alias of the
   mailserver that you don't have listed).

   Occasionally these errors indicate the sort of header-parsing problem
   described in M7.

M2. I can't seem to get fetchmail to route to a local domain properly.

   A lot of people want to use fetchmail as a poor man's internetwork mail
   gateway, picking up mail accumulated for a whole domain in a single
   server mailbox and then routing based on what's in the To/Cc/Bcc lines.

   In general, this is not really a good idea. It would be smarter to just
   let the mail sit in the mailserver's queue and use fetchmail's ETRN or
   ODMR modes to trigger SMTP sends periodically (of course, this means
   you have to poll more frequently than the mailserver's expiration
   period). If you can't arrange this, try setting up a UUCP feed.

   If neither of these alternatives is available, multidrop mode may do
   (though you are going to get hurt by some mailing list software; see
   the caveats under THE USE AND ABUSE OF MULTIDROP MAILBOXES on the man
   page, and check what is needed at Matthias Andree's "Requisites for
   working multidrop mailboxes"). If you want to try it, the way to do it
   is with the 'localdomains' option.

   In general, if you use localdomains you need to make sure of two other
   things:

   1. You've actually set up your .fetchmailrc entry to invoke multidrop
   mode.

   Many people set a 'localdomains' list and then forget that fetchmail
   wants to see more than one name (or the wildcard '*') in a 'here' list
   before it will do multidrop routing.

   2. You may have to set 'no envelope'.

   Normally, multidrop mode tries to deduce an envelope address from a
   message before parsing the To/Cc/Bcc lines (this enables it to avoid
   losing to mailing list software that doesn't put a recipient address in
   the To lines).

   Some ways of accumulating a whole domain's messages in a single server
   mailbox mean it all ends up with a single envelope address that is
   useless for rerouting purposes. In this particular case, sell your ISP
   a clue. If that does not work, you may have to set 'no envelope' to
   prevent fetchmail from being bamboozled by this, but a missing envelope
   makes multidrop routing unreliable.

   Check also answer T1 on a reliable way to do multidrop delivery if your
   ISP (or your mail redirection provider) is using qmail.

M3. I tried to run a mailing list using multidrop, and I have a mail loop!

   This isn't fetchmail's fault. Check your mailing list. If the list
   expansion includes yourself or anybody else at your mailserver (that
   is, not on the client side) you've created a mail loop. Just chop the
   host part off any local addresses in the list.

   If you use sendmail, you can check the list expansion with sendmail
   -bv.

[DEL: M4. My multidrop fetchmail seems to be having DNS problems. :DEL]

   The answer that used to be here no longer applies to fetchmail.

M5. I'm seeing long DNS delays before each message is processed.

   Use the 'aka' option to pre-declare as many of your mailserver's DNS
   names as you can. When an address's host part matches an aka name, no
   DNS lookup needs to be done to check it.

   If you're sure you've pre-declared all of your mailserver's DNS names,
   you can use the 'no dns' option to prevent other hostname parts from
   being looked up at all.

   Sometimes delays are unavoidable. Some SMTP listeners try to call DNS
   on the From-address hostname as a way of checking that the address is
   valid.

M6. How do I get multidrop mode to work with majordomo?

   In order for sendmail to execute the command strings in the majordomo
   alias file, it is necessary for sendmail to think that the mail it
   receives via SMTP really is destined for a local user name. A normal
   virtual-domain setup results in delivery to the default mailbox, rather
   than expansion through majordomo.

   Michael <michael@bizsystems.com> gave us a recipe for dealing with this
   case that pairs a run control file like this:
poll your.pop3.server proto pop3:
    no envelope no dns
    localdomains virtual.localdomain1.com virtual.localdomain2.com ...
    user yourISPusername is root * here,
    password yourISPpassword fetchall

   with a hack on your local sendmail.cf like this:
#############################################
#  virtual info, local hack for ruleset 98  #
#############################################

# domains to treat as direct mapped local domain

CVvirtual.localdomain1.com virtual.localdomain2.com ...
---------------------------
in ruleset 98 add
-------------------------
# handle virtual users

R$+ <@ $=V . >          $: $1 < @ $j . >
R< @ > $+ < @ $=V . >   $: $1 < @ $j . >
R< @ > $+               $: $1
R< error : $- $+ > $*   $#error $@ $1 $: $2
R< $+ > $+ < @ $+ >     $: $>97 $1

   This ruleset just strips virtual domain names off the addresses of
   incoming mail. Your sendmail must be 8.8 or newer for this to work.
   Michael says:

     I use this scheme with 2 virtual domains and the default ISP
     user+domain and service about 30 mail accounts + majordomo on my
     inside pop3 server with fetchmail and sendmail 8.83

M7. Multidrop mode isn't parsing envelope addresses from my Received headers as
it should.

   It may happen that you're getting what appear to be well-formed
   sendmail Received headers, but fetchmail can't seem to extract an
   envelope address from them. There can be a couple of reasons for this.

  Spurious Received lines need to be skipped:

   First, fetchmail might be looking at the wrong Received header.
   Normally it looks only on the first one it sees, on the theory that
   that one was last added and is going to be the one containing your
   mailserver's theory of who the message was addressed to.

   Some (unusual) mailserver configurations will generate extra Received
   lines which you need to skip. To arrange this, use the optional skip
   prefix argument of the 'envelope' option; you may need to say something
   like 'envelope 1 Received' or 'envelope 2 Received'.

  The 'by' clause doesn't contain a mailserver alias:

   When fetchmail parses a Received line that looks like
Received: from send103.yahoomail.com (send103.yahoomail.com [205.180.60.92])
    by iserv.example.net (8.8.5/8.8.5) with SMTP id RAA10088
    for <ksturgeon@fbceg.example.org>; Wed, 9 Sep 1998 17:01:59 -0700

   it checks to see if 'iserv.example.net' is a DNS alias of your
   mailserver before accepting 'ksturgeon@fbceg.example.org' as an
   envelope address. This check might fail if your DNS were misconfigured,
   or if you were using 'no dns' and had failed to declare
   iserv.example.net as an alias of your server. The typical hint is
   logging similar to: line rejected, iserv.example.net is not an alias of
   the mailserver, if you use fetchmail in verbose mode.

   Workaround: You can specify the alias explicitly, with aka
   iserv.example.net statements in the rcfile. Replace iserv.example.net
   by the name you find in your 'by' part of the 'Received:' line.

M8. Users are getting multiple copies of messages.

   It's a consequence of multidrop. What's happening is that you have N
   users subscribed to the same list. The list software sends N copies,
   not knowing they will end up in the same multidrop box. Since they are
   both locally addressed to all N users, fetchmail delivers N copies to
   each user.

   Fetchmail tries to eliminate adjacent duplicate messages in a multidrop
   mailbox. However, this logic depends on the message-ID being identical
   in both copies. It also depends on the two copies being adjacent in the
   server mailbox. The former is usually the case, but the latter
   condition sometimes fails in a timing-dependent way if the server was
   processing multiple incoming mail streams.

   I could eliminate this problem by keeping a list of all message-IDs
   received during a poll so far and dropping any message that matches a
   seen mail ID. The trouble is that this is an O(N**2) operation that
   might significantly slow down the retrieval of large mail batches.

   The real solution however is to make sure that fetchmail can find the
   envelope recipient properly, which will reliably prevent this message
   duplication.
     __________________________________________________________________

                                  Mangled mail

X1. Spurious blank lines are appearing in the headers of fetched mail.

   What's probably happening is that the POP/IMAP daemon on your
   mailserver is inserting a non-RFC822 header (like X-POP3-Rcpt:) and
   something in your delivery path (most likely an old version of the
   deliver program, which sendmail often calls to do local delivery) is
   failing to recognize it as a header.

   This is not fetchmail's problem. The first thing to try is installing a
   current version of deliver. If this doesn't work, try to figure out
   which other program in your mail path is inserting the blank line and
   replace that. If you can't do either of these things, pick a different
   MDA (such as maildrop) and declare it with the 'mda' option.

X2. My mail client can't see a Subject line.

   First, see X1. This is quite probably the same problem (X-POP3-Rcpt
   header or something similar being inserted by the server and choked on
   by an old version of deliver).

   The O'Reilly sendmail book does warn that IDA sendmail doesn't process
   X- headers correctly. If this is your problem, all I can suggest is
   replacing IDA sendmail, because it's broken and not RFC822 conformant.

X3. Messages containing "From" at the start of line are being split.

   If you know the messages aren't split in your server mailbox, then this
   is a problem with your POP/IMAP server, your client-side SMTP listener
   or your local delivery agent. Fetchmail cannot split messages.

   Some POP server daemons ignore Content-Length headers and split
   messages on From lines. We have one report that the 2.1 version of the
   BSD popper program (as distributed on Solaris 2.5 and elsewhere) is
   broken this way.

   You can test this. Declare an mda of 'cat' and send yourself one piece
   of mail containing "From" at start of a line. If you see a split
   message, your POP/IMAP server is at fault. Upgrade to a more recent
   version.

   Sendmail and other SMTP listeners don't split RFC822 messages either.
   What's probably happening is either sendmail's local delivery agent or
   your mail reader are not quite RFC822-conformant and are breaking
   messages on what it thinks are Unix-style From headers. You can figure
   out which by looking at your client-side mailbox with vi or more. If
   the message is already split in your mailbox, your local delivery agent
   is the problem. If it's not, your mailreader is the problem.

   If you can't replace the offending program, take a look at your
   sendmail.cf file. There will likely be a line something like
Mlocal, P=/usr/bin/procmail, F=lsDFMShP, S=10, R=20/40, A=procmail -Y -d $u

   describing your local delivery agent. Try inserting the 'E' option in
   the flags part (the F= string). This will make sendmail turn each
   dangerous start-of-line From into a >From, preventing programs further
   downstream from acting up.

X4. My mail is being mangled in a new and different way

   The first thing you need to do is pin down what program is doing the
   mangling. We don't like getting bug reports about fetchmail that are
   actually due to some other program's malfeasance, so please go through
   this diagnostic sequence before sending us a complaint.

   There are five possible culprits to consider, listed here in the order
   they pass your mail:
    1. Programs upstream of your server mailbox.
    2. The POP or IMAP server on your mailserver host.
    3. The fetchmail program itself.
    4. Your local sendmail.
    5. Your LDA (local delivery agent), as called by sendmail or specified
       by mda.

   Often it happens that fetchmail itself is OK, but using it exposes
   pre-existing bugs in your downstream software, or your downstream
   software has a bad interaction with POP/IMAP. You need to pin down
   exactly where the message is being garbled in order to deduce what is
   actually going on.

   The first thing to do is send yourself a test message, and retrieve it
   with a .fetchmailrc entry containing the following (or by running with
   the equivalent command-line options):
    mda "cat >MBOX" keep fetchall

   This will capture what fetchmail gets from the server, except for (a)
   the extra Received header line fetchmail prepends, (b) header address
   changes due to rewrite, and (c) any end-of-line changes due to the
   forcecr and stripcr options. MBOX will in fact contain what programs
   downstream of fetchmail see.

   The most common causes of mangling are bugs and misconfigurations in
   those downstream programs. If MBOX looks unmangled, you will know that
   is what is going on and that it is not fetchmail's problem. Take a look
   at the other FAQ items in this section for possible clues about how to
   fix your problem.

   If MBOX looks mangled, the next thing to do is compare it with your
   actual server mailbox (if possible). That's why you specified keep, so
   the server copy would not be deleted. If your server mailbox looks
   mangled, programs upstream of your server mailbox are at fault.
   Unfortunately there is probably little you can do about this aside from
   complaining to your site postmaster, and nothing at all fetchmail can
   do about it!

   More likely you'll find that the server copy looks OK. In that case
   either the POP/IMAP server or fetchmail is doing the mangling. To
   determine which, you'll need to telnet to the server port and simulate
   a fetchmail session yourself. This is not actually hard (both POP3 and
   IMAP are simple, text-only, line-oriented protocols) but requires some
   attention to detail. You should be able to use a fetchmail -v log as a
   model for a session, but remember that the "*" in your LOGIN or PASS
   command dump has to be replaced with your actual password.

   The objective of manually simulating fetchmail is so you can see
   exactly what fetchmail sees. If you see a mangled message, then your
   server is at fault, and you probably need to complain to your
   mailserver administrators. However, we like to know what the broken
   servers are so we can warn people away from them. So please send us a
   transcript of the session including the mangling and the server's
   initial greeting line. Please tell us anything else you think might be
   useful about the server, like the server host's operating system.

   If your manual fetchmail simulation shows an unmangled message,
   congratulations. You've found an actual fetchmail bug, which is a
   pretty rare thing these days. Complain to us and we'll fix it. Please
   include the session transcript of your manual fetchmail simulation
   along with the other things described in the FAQ entry on reporting
   bugs.

[DEL: X5. Using POP3, retrievals seems to be fetching too much! :DEL]

   The information that used to be here pertained to fetchmail 4.4.7 or
   older, which should not be used. Use a recent fetchmail version.

X6. My mail attachments are being dropped or mangled.

   Fetchmail doesn't discard attachments; fetchmail doesn't have any idea
   that attachments are there. Fetchmail treats the body of each message
   as an uninterpreted byte stream and passes it through without
   alteration. If you are not receiving attachments through fetchmail, it
   is because your mailserver is not sending them to you.

   The fix for this is to replace your mailserver with one that works. If
   its operating system makes this difficult, you should replace its
   operating system with one that works. Windows- and NT-based POP servers
   seem especially prone to mangle attachments. If you are running one of
   these, replacing your server with a Unix machine is probably the only
   effective solution.

   We've had sporadic reports of problems with Microsoft Exchange and
   Outlook servers. These sometimes randomly fail to ship attachments to
   your client. This is a known bug, acknowledged by Microsoft.

   They may also mangle the attachments they do pass through. If you see
   unreadable attachments with a ContentType of "application/x-tnef",
   you're having this problem. The TNEF utility may help.

   The Mail Max POP3 server and the InterChange and Imail IMAP servers are
   known to simply drop MIME attachments when uploading messages.

   We've also had a report that Lotus Notes sometimes trashes the MIME
   type of messages. In particular, it seems to modify MIME headers of
   type application/pdf, mangling the type to application/octet-stream. It
   may corrupt other MIME types as well.

   The IMAP service of Lotus Domino has a known bug in the way it
   generates MIME Content-type headers (observed on Lotus Domino 5.0.2b).
   It's a subtle one that doesn't show up when Netscape Messenger and
   other clients use a FETCH BODY[] to grab the whole message. When
   fetchmail uses FETCH RFC822.HEADER and FETCH RFC822.TEXT to get first
   the header and then the body, Domino generates different Boundary tags
   for each part, e.g. one tag is declared in the Content-type header and
   another is used to separate the MIME parts in the body. This doesn't
   work. (I have heard a rumor that this bug is scheduled to be fixed in
   Domino release 6; you can find a workaround at contrib/domino.)

   Rob Funk explains: Unfortunately there also remain many mail user
   agents that don't write correct MIME messages. One big offender is Sun
   MailTool attachments, which are formatted enough like MIME that some
   programs could get confused; these are generated by the mailtool and
   dtmail programs (the mail programs in Sun's OpenWindows and CDE
   environments).

   One solution to problems related to misformatted MIME attachments is
   the emil program; see its tutorial file at that site for details on
   emil. It is useful for converting character sets, attachment encodings,
   and attachment formats. At this writing, emil does not appear to have
   been maintained since a patch to version 2.1.0beta9 in late 1997, but
   it is still useful.

   One good way of using emil is from within procmail. You can have
   procmail look for signs of problematic message formatting, and pipe
   those messages through emil to be fixed. emil will not always be able
   to fix the problem, in which case the message is unchanged.

   A possible rule to be inserted into a .procmailrc file for using emil
   would be:
:0HB
* 1^1 ^Content-Type: \/X-sun[^;]*
* 1^1 ^Content-Type: \/application/mac-binhex[^;]*
* 1^1 ^Content-Transfer-Encoding: \/x-binhex[^;]*
* 1^1 ^Content-Transfer-Encoding: \/x-uuencode[^;]*
{
  LOG="Converting $MATCH
"
  :0fw
  | emil -A B -T Q -B BA -C iso-8859-1 -H Q -F MIME \
  | gawk '{gsub(/\r\n?/,"\n");print $0}'
}

   The "1^1" in the conditions is a way of specifying to procmail that if
   any one of the four listed expressions is found in the message, the
   total condition is considered true, and the message gets passed into
   emil. These four subconditions check whether the message has a Sun
   attachment, a binhex attachment, or a uuencoded attachment; there are
   others that could be added to check these things better and to check
   other relevant conditions. The "LOG=" line writes a line into the
   procmail log; the lone double-quote beginning the following line makes
   sure the log entry gets an end-of-line character. The call to gawk (GNU
   awk) is for fixing end-of-line conventions, since emil sometimes leaves
   those in the format of the originating machine; it could probably be
   replaced with a sed subsitution.

   The emil call itself tries to ensure that the message uses:
     * BinHex encoding for any Apple Macintosh-only attachments
     * Quoted-Printable encoding for text (when necessary)
     * Base64 Encoding for binary attachments
     * iso-8859-1 character set for text (unfortunately emil can't yet
       convert from windows-1252 to iso-8859-1)
     * Quoted-Printable encoding for headers
     * MIME attachment format

   Most of these (the primary exceptions being the character set and the
   Apple binary format) are as they should be for good internet
   interoperability.

   Some mail servers (Lotus Domino is a suspect here) mangle Sun-formatted
   messages, so the conversion to MIME needs to happen before such
   programs see the message. The ideal is to rid the world of
   Sun-formatted messages: don't use mailtool for sending attachments (it
   doesn't understand MIME anyway, and most of the world doesn't
   understand its attachments, so it really shouldn't be used at all), and
   make sure dtmail is set to use MIME rather than mailtool's format.

X7. Some mail attachments are hanging fetchmail.

   Fetchmail doesn't know anything about mail attachments and doesn't
   treat them any differently from plain message data.

   The most usual cause of this problem seems to be bugs in your network
   transport layer's capability to handle the very large TCP/IP packets
   that attachments tend to turn into. You can test this theory by trying
   to download the offending message through a webmail account; using HTTP
   for the message tends to simulate large-packet stress rather well, and
   you will probably find that the messages that seem to be choking
   fetchmail will make your HTTP download speed drop to zero.

   This problem can be caused by subtle bugs in the packet-reassembly
   layer of your TCP/IP stack; these often don't manifest at normal packet
   sizes. It may also be caused by malfunctioning path-MTU discovery on
   the mailserver. Or, if there's a modem in the link, it may be because
   the attachment contains the Hayes mode escape "+++".

X8. A spurious ) is being appended to my messages.

   Fetchmail 6.3.5 and newer releases are supposed to fix this.

   Due to the problem described in S2, the IMAP support in fetchmail
   cannot follow the IMAP protocol 100 %. Most of the time it doesn't
   matter, but if you combine it with an SMTP server that behaves
   unusually, you'll get a spurious ) at the message end.

   One piece of software that can trigger this is the Interchange mail
   server, as used by, e.g., mailandnews.com. Here's what happens:
    1. Someone sends mail to your account. The last line of the message
       contains text. So at the SMTP level, the message ends with, e.g.
       "blahblah\r\n.\r\n"
    2. The SMTP handler sees the final "\r\n.\r\n" and recognizes the end
       of the message. However, instead of doing the normal thing, which
       is tossing out the ".\r\n" and leaving the first '\r\n' as part of
       the email body, Interchange throws out the whole "\r\n.\r\n", and
       leaves the email body without any line terminator at the end of it.
       RFC821 does not forbid this, though it probably should.
    3. Fetchmail, or some other IMAP client, asks for the message. IMAP
       returns it, but it's enclosed inside parentheses, according to the
       protocol. The message size in bytes is also present. Because the
       message doesn't end with a line terminator, the IMAP client sees:
 ....blahblah)...

       where the ')' is from IMAP.
    4. Fetchmail only deals with complete lines, and can't trust the
       stated message size because Microsoft Exchange goofs it up.
    5. As a result, fetchmail takes the final 'blahblah)' and puts it at
       the end of the message it forwards on. If you have verbosity on,
       you'll get a message about actual != expected.

X9. Missing "Content-Transfer-Encoding" header with Domino IMAP

   Domino 6 IMAP was found by Anthony Kim in February 2006 to erroneously
   omit the "Content-Transfer-Encoding" header in messages downloaded
   through IMAP, causing messages to display improperly. This happened
   with Domino's incoming mail format configured to "Prefers MIME".
   Solution: switch Domino to "Keep in Sender's format".

   Reference: Anthony Kim's list post

X10. Fetchmail delivers partial messages

   Fetchmail is sometimes reported to deliver partial messages. This is
   usually related to network outages that occur while fetchmail is
   downloading a message body. In such cases, fetchmail has downloaded a
   complete header, so your header will be intact. The message body will
   be truncated, and fetchmail will later attempt to redownload the
   message (providing the server is standards conformant).

   The reason for the truncation is that fetchmail streams the body
   directly from the POP3/IMAP server into the SMTP/LMTP server or MDA (in
   order to save memory), so fetchmail has already written a part of the
   message before it notices it will be incomplete, and fetchmail cannot
   abort a transaction it has started, and it's unclear if it ever will be
   able to, because this is not standardized and the outcome will depend
   on the receiving software (be it SMTP/LMTP or MDA).
     __________________________________________________________________

                                 Other problems

O1. The --logfile option doesn't work if the logfile doesn't exist.

   This is a feature, not a bug. It's in line with normal practice for
   system daemons and allows you to suppress logging by removing the log
   file, without hacking potentially fragile startup scripts. To get
   around it, just touch(1) the logfile before you run fetchmail (this
   will have no effect on the contents of the logfile if it already
   exists).

O2. Every time I get a POP or IMAP message, the header is dumped to all my
terminal sessions.

   Fetchmail uses the local sendmail to perform final delivery, which
   Mozilla and other clients don't do; the announcement of new messages is
   done by a daemon that sendmail pokes. There should be a "biff" command
   to control this. Type
biff n

   to turn it off. If this doesn't work, try the command
chmod -x $(tty)

   which is essentially what biff -n will do. If this doesn't work,
   comment out any reference to "comsat" in your /etc/inetd.conf file and
   reload (or restart) inetd.

   In Slackware Linux distributions, the last line in /etc/profile is
biff y

   Change this to
biff n

   to solve the problem system-wide.

O3. Does fetchmail reread its rc file every poll cycle?

   No, but versions 5.2.2 and later will notice when you modify your rc
   file and restart, reading it. Note that this causes troubles if you
   need to provide a password via the console, unless you're running in
   --nodetach mode.

O4. Why do deleted messages show up again when I take a line hit while
downloading?

   According to the POP3 RFCs, deletes aren't actually performed until you
   issue the end-of-session QUIT command. Fetchmail cannot fix this, but
   there is a workaround: use the --expunge option with a reasonably low
   figure that works for you. Try 10 for a start.

   IMAP is less susceptible to this problem, because the "deleted" message
   marks are persistent, but they aren't in POP3. Note that the --expunge
   default for IMAP is different than the default for POP3.

   If you get very unlucky, you might take a line hit in the window
   between the delete and the expunge. If you've set a longer expunge
   interval, the window gets wider. This problem should correct itself the
   next time you complete a successful query.

O5. Why is fetched mail being logged with my name, not the real From address?

   Because logging is done based on the address indicated by the sending
   SMTP's MAIL FROM, and some listeners are picky about that address.

   Some SMTP listeners get upset if you try to hand them a MAIL FROM
   address naming a different host than the originating site for your
   connection. This is a feature, not a bug -- it's supposed to help
   prevent people from forging mail with a bogus origin site. (RFC 1123
   says you shouldn't do this exclusion...)

   Since the originating site of a fetchmail delivery connection is
   localhost, this effectively means these picky listeners will barf on
   any MAIL FROM address fetchmail hands them with an @ in it!

   Versions 2.1 and up try the header From address first and fall back to
   the calling-user ID. So if your SMTP listener isn't picky, the log will
   look right.

O6. I'm seeing long sendmail delays or hangs near the start of each poll cycle.

   Sendmail does a hostname lookup when it first starts up, and also each
   time it gets a HELO in listener mode.

   Your resolver configuration may be causing one of these lookups to fail
   and time out. Check your /etc/resolv.conf, /etc/host.conf,
   /etc/nsswitch.conf (if you have the latter two) and you /etc/hosts
   files. Make sure your hostname and fully-qualified domain name are both
   in /etc/hosts, and that hosts is looked at before DNS is queried. You
   probably also want your remote mail server(s) to be in the hosts file.

   You can suppress the startup-time lookup if need to by reconfiguring
   with FEATURE(nodns).

   Configuring your bind library to cache DNS lookups locally may help,
   and is a good idea for speeding up other services as well. Switching to
   a faster MTA like Postfix might help.

O7. Why doesn't fetchmail deliver mail in date-sorted order?

   Because that's not the order the server hands it to fetchmail in.

   Fetchmail getting mail from a POP server delivers mail in the order
   that your server delivers mail. Fetchmail can't do anything about this;
   it's a limitation of the underlying POP protocol.

   In theory it might be possible for fetchmail in IMAP mode to sort
   messages by date, but this would be in violation of two basics of
   fetchmail's design philosophy: (a) to be as simple and transparent a
   pipe as possible, and (b) to hide, rather than emphasize, the
   differences between the remote-fetch protocols it uses.

   Re-ordering messages is a user-agent function, anyway.

O8. I'm using pppd. Why isn't my monitor option working?

   There is a combination of circumstances that can confuse fetchmail. If
   you have set up demand dialing with pppd, and pppd has an idle timeout,
   and you have lcp-echo-interval set, then the lcp-echo-interval time
   must be longer than the pppd idle timeout. Otherwise it is going keep
   increasing the packet counters that fetchmail relies upon, triggering
   fetchmail into polling after its own delay interval and thus preventing
   the pppd link from ever reaching its inactivity timeout.

O9. Why does fetchmail keep retrieving the same messages over and over?

   First, check to see that you haven't enabled the keep and fetchall
   option. If you have, turn one of them off - which one, depends on why
   they have been set in the first place, and to a lesser degree on the
   upstream server.

   This can also happen when some other mail client is logged in to your
   mail server, if it uses a simple exclusive-locking scheme (and many,
   especially most POP3 servers, do exactly that). Your fetchmail is able
   to retrieve the messages, but because the mailbox is write-locked by
   the other instance yours can neither mark messages seen or delete them.
   The solution is to either (a) wait for the other client to finish, or
   (b) terminate it.

[DEL: O10. Why is the received date on all my messages the same? :DEL]

   The answer that used to be here made no sense and was dropped.

O11. I keep getting messages that say "Repoll immediately" in my logs.

   This is your server barfing on the CAPA probe that fetchmail sends.
   Because some servers like to drop the connection after that probe,
   fetchmail will re-poll immediately with this probe defeated.

   If you run fetchmail in daemon mode (say "set daemon 600"), you will
   get the message only once per run.

   If you set an authentication method explicitly (say, with auth
   password), you will never get the message.

O12. Fetchmail no longer expunges mail on a 451 SMTP response.

   This is a feature, not a bug.

   Any 4xx response (like 451) indicates a transient (temporary) error.
   This means that the mail could be accepted if retried later. Lookup
   failures are normally transient errors as a mail should not get
   rejected if a dns server is unreachable or down.

   A permanent reject response is of the form 5xx (like 550).

   You could tell your SMTP server to not lookup any addresses if you are
   not keen on checking the sender addresses. This problem typically
   occurs if your mail server is not checking the sender addresses, but
   your local server is.

   Or you could declare antispam 451, which is not recommended though, as
   it may cause mail loss.

   Or, you could check your nameserver configuration and query logs for
   dns errors.

   All these issues are not related to fetchmail directly.

O13. I want timestamp information in my fetchmail logs.

   Write a preconnect command in your configuration file that does
   something like "date >> $HOME/fetchmail.log".

O14. Fetchmail no longer deletes oversized mails with --flush.

   Use --limitflush (available since release 6.3.0) to delete oversized
   mails along with the --limit option. If you are already having flush in
   your rcfile to delete oversized mails, replace it with limitflush to
   avoid losing mails unintentionally.

   The --flush option is primarily designed to delete mails which have
   been read/downloaded but not deleted yet. This option cannot be
   overloaded to delete oversized mails as it cannot be guessed whether
   the user wants to delete only read/downloaded mails or only oversized
   mails or both when a user specifies both --limit and --flush. Hence, a
   separate --limitflush has been added to resolve the ambiguity.

O15. Fetchmail always retains the first message in the mailbox.

   This happens when fetchmail sees an "X-IMAP:" header in the very first
   message in your mailbox. This usually stems from a message like the one
   shown below, which is automatically created on your server. This
   message shows up if the University of Washington IMAP or PINE software
   is used on the server together with a POP2 or POP3 daemon that is not
   aware of these messages, such as some versions of Qualcomm Popper
   (QPOP):

From MAILER-DAEMON Wed Nov 23 11:38:42 2005
Date: 23 Nov 2005 11:38:42 +0100
From: Mail System Internal Data <MAILER-DAEMON@imap.example.org>
Subject: DON'T DELETE THIS MESSAGE -- FOLDER INTERNAL DATA
Message-ID: <1132742322@imap.example.org>
X-IMAP: 1132742306 0000000001
Status: RO

This text is part of the internal format of your mail folder, and is not
a real message.  It is created automatically by the mail system software.
If deleted, important folder data will be lost, and it will be re-created
with the data reset to initial values.

   As this message does not contain useful information, fetchmail is not
   retrieving it. And deleting it might slow down the server if you are
   keeping messages on the server, and the server would recreate it
   anyways, that's why fetchmail does not bother to delete it either.

O16. Why is the Fetchmail FAQ only available in ISO-216 A4 format? How do I get
the FAQ in Letter format?

   All the world uses ISO-216:1975 "A4" paper except for North America.
   Using A4 format reaches far more people than (formerly known as DIN A4,
   from DIN 476) format. Besides that, A4 paper is available in North
   America. For further information on the Letter-vs-A4 story, see:
     * Markus Kuhn: "International standard paper sizes"
     * Brian Forte: "A4 vs US Letter"

   Offering the document formatted for two different paper sizes would
   bloat the package beyond reason, and formatting in a way that fits A4
   and Letter paper formats would be a waste of paper in most parts of the
   world. For that reason, fetchmail only ships with an A4 formatted PDF
   document.

   To create a letter-sized PDF, install HTMLDOC, edit fetchmail-FAQ.book
   in the source directory with your favorite text editor, replace --size
   A4 by --size letter, and type:
make fetchmail-FAQ.pdf

O17. Linux logs "TCP(fetchmail:...): Application bug, race in MSG_PEEK."

   That's in fact a bug in Linux kernels around the late 2.6.2X versions,
   rather than fetchmail. Fetchmail has no race bugs around MSG_PEEK, as
   of version 6.3.9. The message can safely be ignored.
     __________________________________________________________________


    Eric S. Raymond <esr@thyrsus.com>
    Matthias Andree
