IMAPSYNC(1)

NAME
imapsync - Email IMAP tool for syncing, copying and migrating email mailboxes between two imap servers, one way, and without duplicates.

VERSION
This documentation refers to Imapsync $Revision: 1.945 $

USAGE
 To synchronize the source imap account
   "test1" on server "test1.lamiral.info" with password "secret1"
 to the destination imap account
   "test2" on server "test2.lamiral.info" with password "secret2"
 do:

  imapsync \
   --host1 test1.lamiral.info --user1 test1 --password1 secret1 \
   --host2 test2.lamiral.info --user2 test2 --password2 secret2

DESCRIPTION
We sometimes need to transfer mailboxes from one imap server to one another.

Imapsync command is a tool allowing incremental and recursive imap transfers from one mailbox to another. If you don't understand the previous sentence, it's normal, it's pedantic computer oriented jargon.

All folders are transferred, recursively, meaning the whole folder hierarchy is taken, all messages in them, and all messages flags (\Seen \Answered \Flagged etc.) are synced too.

Imapsync reduces the amount of data transferred by not transferring a given message if it already resides on the destination side. Messages that are on the destination side but not on the source side stay as they are (see the --delete2 option to have a strict sync).

How imapsync knows a message is already on both sides? Same specific headers and the transfer is done only once. By default, the identification headers are "Message-Id:" and "Received:" lines but this choice can be changed with the --useheader option.

All flags are preserved, unread messages will stay unread, read ones will stay read, deleted will stay deleted.

You can abort the transfer at any time and restart it later, imapsync works well with bad connections and interruptions, by design. On a terminal hit Ctr-c twice within two seconds in order to abort the program. Hit Ctr-c just once makes imapsync reconnect to both imap servers.

A classical scenario is synchronizing a mailbox B from another mailbox A in case you just want to keep a strict copy of A in B. Strict meaning all messages in A will be in B but no more.

For this, option --delete2 has to be used, it deletes messages in host2 folder B that are not in host1 folder A. If you also need to destroy host2 folders that are not in host1 then use --delete2folders. See also --delete2foldersonly and --delete2foldersbutnot to set up exceptions on folders to destroy (INBOX will never be destroy, it's a mandatory folder in IMAP).

A different scenario is to delete the messages from the source mailbox after a successful transfer, it can be a good feature when migrating mailboxes since messages will be only on one side. The source account will only have messages that are not on the destination yet, ie, messages that arrived after a sync or that failed to be copied.

In that case, use the --delete1 option. Option --delete1 implies also option --expunge1 so all messages marked deleted on host1 will be really deleted. In IMAP protocol deleting a message does not really delete it, it marks it with the flag \Deleted, allowing an undelete. Expunging a folder removes, definitively, all the messages marked as \Deleted in this folder.

You can also decide to remove empty folders once all of their messages have been transferred. Add --delete1emptyfolders to obtain this behavior.

Imapsync is not adequate for maintaining two active imap accounts in synchronization when the user plays independently on both sides. Use offlineimap (written by John Goerzen) or mbsync (written by Michael R. Elkins) for a 2 ways synchronization.

OPTIONS
 usage: imapsync [options]

Standard options are the six values forming the credentials, three on each sides, needed to log in into the IMAP servers, ie, a host, a username, and a password, two times.

Conventions used:

 str means string
 int means integer
 reg means regular expression
 cmd means command

 --dry               : Makes imapsync doing nothing for real, just print what
                       would be done without --dry.

  OPTIONS/credentials
 --host1        str  : Source or "from" imap server.
 --port1        int  : Port to connect on host1.
                       Optional since default ports are the
                       well known ports 143 or 993.
 --user1        str  : User to login on host1.
 --password1    str  : Password for the user1.

 --host2        str  : "destination" imap server.
 --port2        int  : Port to connect on host2. Optional
 --user2        str  : User to login on host2.
 --password2    str  : Password for the user2.

 --showpasswords     : Shows passwords on output instead of "MASKED".
                       Useful to restart a complete run by just reading
                       the command line used in the log,
                       or to debug passwords.
                       It's not a secure practice.

 --passfile1    str  : Password file for the user1. It must contain the
                       password on the first line. This option avoids showing
                       the password on the command line like --password1 does.
 --passfile2    str  : Password file for the user2.

You can also pass the passwords in the environment variables IMAPSYNC_PASSWORD1 and IMAPSYNC_PASSWORD2

  OPTIONS/encryption
 --nossl1            : Do not use a SSL connection on host1.
 --ssl1              : Use a SSL connection on host1. On by default if possible.

 --nossl2            : Do not use a SSL connection on host2.
 --ssl2              : Use a SSL connection on host2. On by default if possible.

 --notls1            : Do not use a TLS connection on host1.
 --tls1              : Use a TLS connection on host1. On by default if possible.

 --notls2            : Do not use a TLS connection on host2.
 --tls2              : Use a TLS connection on host2. On by default if possible.

 --debugssl     int  : SSL debug mode from 0 to 4.

 --sslargs1     str  : Pass any ssl parameter for host1 ssl or tls connection. Example:
                       --sslargs1 SSL_verify_mode=1 --sslargs1 SSL_version=SSLv3
                       See all possibilities in the new() method of IO::Socket::SSL
                       http://search.cpan.org/perldoc?IO::Socket::SSL#Description_Of_Methods
 --sslargs2     str  : Pass any ssl parameter for host2 ssl or tls connection.
                       See --sslargs1

 --timeout1     int  : Connection timeout in seconds for host1.
                       Default is 120 and 0 means no timeout at all.
 --timeout2     int  : Connection timeout in seconds for host2.
                       Default is 120 and 0 means no timeout at all.

  OPTIONS/authentication
 --authmech1    str  : Auth mechanism to use with host1:
                       PLAIN, LOGIN, CRAM-MD5 etc. Use UPPERCASE.
 --authmech2    str  : Auth mechanism to use with host2. See --authmech1

 --authuser1    str  : User to auth with on host1 (admin user).
                       Avoid using --authmech1 SOMETHING with --authuser1.
 --authuser2    str  : User to auth with on host2 (admin user).
 --proxyauth1        : Use proxyauth on host1. Requires --authuser1.
                       Required by Sun/iPlanet/Netscape IMAP servers to
                       be able to use an administrative user.
 --proxyauth2        : Use proxyauth on host2. Requires --authuser2.

 --authmd51          : Use MD5 authentication for host1.
 --authmd52          : Use MD5 authentication for host2.
 --domain1      str  : Domain on host1 (NTLM authentication).
 --domain2      str  : Domain on host2 (NTLM authentication).

  OPTIONS/folders
 --folder       str  : Sync this folder.
 --folder       str  : and this one, etc.
 --folderrec    str  : Sync this folder recursively.
 --folderrec    str  : and this one, etc.

 --folderfirst  str  : Sync this folder first. --folderfirst "Work"
 --folderfirst  str  : then this one, etc.
 --folderlast   str  : Sync this folder last. --folderlast "[Gmail]/All Mail"
 --folderlast   str  : then this one, etc.

 --nomixfolders      : Do not merge folders when host1 is case-sensitive
                       while host2 is not (like Exchange). Only the first
                       similar folder is synced (example: with folders
                       "Sent", "SENT" and "sent"
                       on host1 only "Sent" will be synced to host2).

 --skipemptyfolders  : Empty host1 folders are not created on host2.

 --include      reg  : Sync folders matching this regular expression
 --include      reg  : or this one, etc.
                       If both --include --exclude options are used, then
                       include is done before.
 --exclude      reg  : Skips folders matching this regular expression
                       Several folders to avoid:
                        --exclude 'fold1|fold2|f3' skips fold1, fold2 and f3.
 --exclude      reg  : or this one, etc.

 --automap           : guesses folders mapping, for folders well known as
                       "Sent", "Junk", "Drafts", "All", "Archive", "Flagged".

 --f1f2    str1=str2 : Force folder str1 to be synced to str2,
                       --f1f2 overrides --automap and --regextrans2.

 --subfolder2   str  : Syncs the whole host1 folders hierarchy under the
                       host2 folder named str.
                       It does it internally by adding three
                       --regextrans2 options before all others.
                       Add --debug to see what's really going on.

 --subfolder1   str  : Syncs the host1 folders hierarchy under str
                       to the root hierarchy of host2.
                       It's the couterpart of a sync done by --subfolder2
                       when doing it in the reverse order.
                       Backup/Restore scenario:
                       Use --subfolder2 str for a backup to the folder str
                       on host2. Then use --subfolder1 str for restoring
                       from the folder str, after inverting
                       host1/host2 user1/user2 values.

 --subscribed        : Transfers subscribed folders.
 --subscribe         : Subscribe to the folders transferred on the
                       host2 that are subscribed on host1. On by default.
 --subscribeall      : Subscribe to the folders transferred on the
                       host2 even if they are not subscribed on host1.

 --prefix1      str  : Remove prefix str to all destination folders,
                       usually "INBOX." or "INBOX/" or an empty string "".
                       imapsync guesses the prefix if host1 imap server
                       does not have NAMESPACE capability. So this option
                       should not be used, most of the time.
 --prefix2      str  : Add prefix to all host2 folders. See --prefix1

 --sep1         str  : Host1 separator. This option should not be used,
                       most of the time.
                       Imapsync gets the separator from the server itself,
                       by using NAMESPACE, or it tries to guess it
                       from the folders listing (it counts
                       characters / . \\ \ in folder names and choose the
                       more frequent, or finally / if nothing is found.
 --sep2         str  : Host2 separator.

 --regextrans2  reg  : Apply the whole regex to each destination folders.
 --regextrans2  reg  : and this one. etc.
                       When you play with the --regextrans2 option, first
                       add also the safe options --dry --justfolders
                       Then, when happy, remove --dry, remove --justfolders.
                       Have in mind that --regextrans2 is applied after
                       the automatic prefix and separator inversion.
                       For examples see:
                       https://imapsync.lamiral.info/FAQ.d/FAQ.Folders_Mapping.txt

  OPTIONS/folders sizes
 --nofoldersizes     : Do not calculate the size of each folder at the
                       beginning of the sync. Default is to calculate them.
 --nofoldersizesatend: Do not calculate the size of each folder at the
                       end of the sync. Default is to calculate them.
 --justfoldersizes   : Exit after having printed the initial folder sizes.

  OPTIONS/tmp
 --tmpdir       str  : Where to store temporary files and subdirectories.
                       Will be created if it doesn't exist.
                       Default is system specific, Unix is /tmp but
                       /tmp is often too small and deleted at reboot.
                       --tmpdir /var/tmp should be better.
 --pidfile      str  : The file where imapsync pid is written,
                       it can be dirname/filename.
                       Default name is imapsync.pid in tmpdir.
 --pidfilelocking    : Abort if pidfile already exists. Useful to avoid
                       concurrent transfers on the same mailbox.

  OPTIONS/log
 --nolog             : Turn off logging on file
 --logfile      str  : Change the default log filename (can be dirname/filename).
 --logdir       str  : Change the default log directory. Default is LOG_imapsync/

  OPTIONS/messages
 --skipmess     reg  : Skips messages matching the regex.
                       Example: 'm/[\x80-ff]/' # to avoid 8bits messages.
                       --skipmess is applied before --regexmess
 --skipmess     reg  : or this one, etc.

 --pipemess     cmd  : Apply this cmd command to each message content
                       before the copy.
 --pipemess     cmd  : and this one, etc.
                       With several --pipemess, the output of each cmd
                       command (STDOUT) is given to the input (STDIN)
                       of the next command.
                       For example,
                       --pipemess cmd1 --pipemess cmd2 --pipemess cmd3
                       is like a Unix pipe:
                       "cat message | cmd1 | cmd2 | cmd3"

 --disarmreadreceipts : Disarms read receipts (host2 Exchange issue)

 --regexmess    reg  : Apply the whole regex to each message before transfer.
                       Example: 's/\000/ /g' # to replace null by space.
 --regexmess    reg  : and this one, etc.

  OPTIONS/flags
 If you encounter flag problems see also:
 https://imapsync.lamiral.info/FAQ.d/FAQ.Flags.txt

 --regexflag    reg  : Apply the whole regex to each flags list.
                       Example: 's/"Junk"//g' # to remove "Junk" flag.
 --regexflag    reg  : then this one, etc.

 --resyncflags       : Resync flags for already transferred messages.
                       On by default.
 --noresyncflags     : Do not resync flags for already transferred messages.
                       May be useful when a user has already started to play
                       with its host2 account.

  OPTIONS/deletions
 --delete1           : Deletes messages on host1 server after a successful
                       transfer. Option --delete1 has the following behavior:
                       it marks messages as deleted with the IMAP flag
                       \Deleted, then messages are really deleted with an
                       EXPUNGE IMAP command. If expunging after each message
                       slows down too much the sync then use
                       --noexpungeaftereach to speed up, expunging will then be
                       done only twice per folder, one at the beginning and
                       one at the end of a folder sync.

 --expunge1          : Expunge messages on host1 just before syncing a folder.
                       Expunge is done per folder.
                       Expunge aims is to really delete messages marked deleted.
                       An expunge is also done after each message copied
                       if option --delete1 is set (unless --noexpungeaftereach).

 --noexpunge1        : Do not expunge messages on host1.

 --delete1emptyfolders : Deletes empty folders on host1, INBOX excepted.
                         Useful with --delete1 since what remains on host1
                         is only what failed to be synced.

 --delete2           : Delete messages in host2 that are not in
                       host1 server. Useful for backup or pre-sync.
                       --delete2 implies --uidexpunge2

 --delete2duplicates : Delete messages in host2 that are duplicates.
                       Works only without --useuid since duplicates are
                       detected with an header part of each message.

 --delete2folders    : Delete folders in host2 that are not in host1 server.
                       For safety, first try it like this (it is safe):
                       --delete2folders --dry --justfolders --nofoldersizes

 --delete2foldersonly   reg : Deleted only folders matching regex.
                              Example: --delete2foldersonly "/^Junk$|^INBOX.Junk$/"

 --delete2foldersbutnot reg : Do not delete folders matching regex.
                              Example: --delete2foldersbutnot "/Tasks$|Contacts$|Foo$/"

 --noexpunge2        : Do not expunge messages on host2.
 --nouidexpunge2     : Do not uidexpunge messages on the host2 account
                       that are not on the host1 account.

  OPTIONS/dates
 If you encounter problems with dates, see also:
 https://imapsync.lamiral.info/FAQ.d/FAQ.Dates.txt

 --syncinternaldates : Sets the internal dates on host2 same as host1.
                       Turned on by default. Internal date is the date
                       a message arrived on a host (Unix mtime).
 --idatefromheader   : Sets the internal dates on host2 same as the
                       ones in "Date:" headers.

  OPTIONS/message selection
 --maxsize      int  : Skip messages larger  (or equal) than  int  bytes
 --minsize      int  : Skip messages smaller (or equal) than  int  bytes
 --maxage       int  : Skip messages older than  int days.
                       final stats (skipped) don't count older messages
                       see also --minage
 --minage       int  : Skip messages newer than  int  days.
                       final stats (skipped) don't count newer messages
                       You can do (+ are the messages selected):
                       past|----maxage+++++++++++++++>now
                       past|+++++++++++++++minage---->now
                       past|----maxage+++++minage---->now (intersection)
                       past|++++minage-----maxage++++>now (union)

 --search       str  : Selects only messages returned by this IMAP SEARCH
                       command. Applied on both sides.
                       For a complete of what can be search see
                       https://imapsync.lamiral.info/FAQ.d/FAQ.Messages_Selection.txt

 --search1      str  : Same as --search but for selecting host1 messages only.
 --search2      str  : Same as --search but for selecting host2 messages only.
                       --search CRIT equals --search1 CRIT --search2 CRIT

 --maxlinelength int : skip messages with a line length longer than  int  bytes.
                       RFC 2822 says it must be no more than 1000 bytes.

 --useheader    str  : Use this header to compare messages on both sides.
                       Ex: Message-ID or Subject or Date.
 --useheader    str    and this one, etc.

 --usecache          : Use cache to speed up the sync.
 --nousecache        : Do not use cache. Caveat: --useuid --nousecache creates
                       duplicates on multiple runs.
 --useuid            : Use UIDs instead of headers as a criterion to recognize
                       messages. Option --usecache is then implied unless
                       --nousecache is used.

  OPTIONS/miscellaneous
 --syncacls          : Synchronizes acls (Access Control Lists).
 --nosyncacls        : Does not synchronize acls. This is the default.
                       Acls in IMAP are not standardized, be careful
                       since one acl code on one side may signify something
                       else on the other one.

 --addheader         : When a message has no headers to be identified,
                       --addheader adds a "Message-Id" header,
                       like "Message-Id: 12345@imapsync", where 12345
                       is the imap UID of the message on the host1 folder.

  OPTIONS/debugging
 --debug             : Debug mode.
 --debugfolders      : Debug mode for the folders part only.
 --debugcontent      : Debug content of the messages transferred. Huge output.
 --debugflags        : Debug mode for flags.
 --debugimap1        : IMAP debug mode for host1. Very verbose.
 --debugimap2        : IMAP debug mode for host2. Very verbose.
 --debugimap         : IMAP debug mode for host1 and host2. Twice very verbose.
 --debugmemory       : Debug mode showing memory consumption after each copy.

 --errorsmax     int : Exit when int number of errors is reached. Default is 50.

 --tests             : Run local non-regression tests. Exit code 0 means all ok.
 --testslive         : Run a live test with test1.lamiral.info imap server.
                       Useful to check the basics. Needs internet connection.
 --testslive6        : Run a live test with ks2ipv6.lamiral.info imap server.
                       Useful to check the ipv6 connectivity. Needs internet.

  OPTIONS/specific
  --gmail1           : sets --host1 to Gmail and options from FAQ.Gmail.txt
  --gmail2           : sets --host2 to Gmail and options from FAQ.Gmail.txt

  --office1          : sets --host1 to Office365 options from FAQ.Exchange.txt
  --office2          : sets --host2 to Office365 options from FAQ.Exchange.txt

  --exchange1        : sets options from FAQ.Exchange.txt, account1 part
  --exchange2        : sets options from FAQ.Exchange.txt, account2 part

  --domino1          : sets options from FAQ.Domino.txt, account1 part
  --domino2          : sets options from FAQ.Domino.txt, account2 part

  OPTIONS/behavior
 --maxmessagespersecond int : limits the number of messages transferred per second.

 --maxbytespersecond int : limits the average transfer rate per second.
 --maxbytesafter     int : starts --maxbytespersecond limitation only after
                           --maxbytesafter amount of data transferred.

 --maxsleep      int : do not sleep more than int seconds.
                       On by default, 2 seconds max, like --maxsleep 2

 --abort             : terminates a previous call still running.
                       It uses the pidfile to know what process to abort.

 --exitwhenover int  : Stop syncing and exits when int total bytes
                       transferred is reached.

 --version           : Print only software version.
 --noreleasecheck    : Do not check for new imapsync release
 --releasecheck      : Check for new imapsync release.
                       it's an http request to
                       http://imapsync.lamiral.info/prj/imapsync/VERSION

 --noid              : Do not send/receive ID command to imap servers.

 --justconnect       : Just connect to both servers and print useful
                       information. Need only --host1 and --host2 options.
                       Obsolete since "imapsync --host1 imaphost" alone
                       implies --justconnect

 --justlogin         : Just login to both host1 and host2 with users
                       credentials, then exit.

 --justfolders       : Do only things about folders (ignore messages).

 --help              : print this help.

 Example: to synchronize imap account "test1" on "test1.lamiral.info"
                     to  imap account "test2" on "test2.lamiral.info"
                     with test1 password "secret1"
                     and  test2 password "secret2"

 imapsync \
    --host1 test1.lamiral.info --user1 test1 --password1 secret1 \
    --host2 test2.lamiral.info --user2 test2 --password2 secret2

SECURITY
You can use --passfile1 instead of --password1 to give the password since it is safer. With --password1 option, on Linux, any user on your host can see the password by using the 'ps auxwwww' command. Using a variable (like IMAPSYNC_PASSWORD1) is also dangerous because of the 'ps auxwwwwe' command. So, saving the password in a well protected file (600 or rw-------) is the best solution.

Imapsync activates ssl or tls encryption by default, if possible.

What detailed behavior is under this "if possible"?

Imapsync activates ssl if the well known port imaps port (993) is open on the imap servers. If the imaps port is closed then it open a normal (clear) connection on port 143 but it looks for TLS support in the CAPABILITY list of the servers. If TLS is supported then imapsync goes to encryption.

If the automatic ssl/tls detection fails then imapsync will not protect against sniffing activities on the network, especially for passwords.

If you want to force ssl or tls just use --ssl1 --ssl2 or --tls1 --tls2

See also the document FAQ.Security.txt in the FAQ.d/ directory or at https://imapsync.lamiral.info/FAQ.d/FAQ.Security.txt

EXIT STATUS
Imapsync will exit with a 0 status (return code) if everything went good. Otherwise, it exits with a non-zero status. Here is the list of the exit code values (an integer between 0 and 255), the names reflects their meaning:

     EX_OK          => 0  ; #/* successful termination */
     EX_USAGE       => 64 ; #/* command line usage error */
     EX_NOINPUT     => 66 ; #/* cannot open input */
     EX_UNAVAILABLE => 69 ; #/* service unavailable */
     EX_SOFTWARE    => 70 ; #/* internal software error */
     EXIT_CATCH_ALL              =>   1 ; # Any other error
     EXIT_BY_SIGNAL              =>   6 ; # Should be 128+n where n is the sig_num
     EXIT_PID_FILE_ERROR         =>   8 ;
     EXIT_CONNECTION_FAILURE     =>  10 ;
     EXIT_TLS_FAILURE            =>  12 ;
     EXIT_AUTHENTICATION_FAILURE =>  16 ;
     EXIT_SUBFOLDER1_NO_EXISTS   =>  21 ;
     EXIT_WITH_ERRORS            => 111 ;
     EXIT_WITH_ERRORS_MAX        => 112 ;
     EXIT_TESTS_FAILED           => 254 ; # Like Test::More API

LICENSE AND COPYRIGHT
Imapsync is free, open, public but not always gratis software cover by the NOLIMIT Public License. See the LICENSE file included in the distribution or just read this simple sentence as it IS the licence text:

 "No limits to do anything with this work and this license."

In case it is not long enough, I repeat:

 "No limits to do anything with this work and this license."

Look at https://imapsync.lamiral.info/LICENSE

AUTHOR
Gilles LAMIRAL <gilles@lamiral.info>

Good feedback good is always welcome. Bad feedback is very often welcome.

Gilles LAMIRAL earns his living by writing, installing, configuring and teaching free, open and often gratis software. Imapsync used to be "always gratis" but now it is only "often gratis" because imapsync is sold by its author, a good way to maintain and support free open public software over decades.

BUGS AND LIMITATIONS
See https://imapsync.lamiral.info/FAQ.d/FAQ.Reporting_Bugs.txt

IMAP SERVERS supported
See https://imapsync.lamiral.info/S/imapservers.shtml

HUGE MIGRATION
If you have many mailboxes to migrate think about a little shell program. Write a file called file.txt (for example) containing users and passwords. The separator used in this example is ';'

The file.txt file contains:

user001_1;password001_1;user001_2;password001_2 user002_1;password002_1;user002_2;password002_2 user003_1;password003_1;user003_2;password003_2 user004_1;password004_1;user004_2;password004_2 user005_1;password005_1;user005_2;password005_2 ...

On Unix the shell program can be:

 { while IFS=';' read  u1 p1 u2 p2; do
        imapsync --host1 imap.side1.org --user1 "$u1" --password1 "$p1" \
                 --host2 imap.side2.org --user2 "$u2" --password2 "$p2" ...
 done ; } < file.txt

On Windows the batch program can be:

  FOR /F "tokens=1,2,3,4 delims=; eol=#" %%G IN (file.txt) DO imapsync ^
  --host1 imap.side1.org --user1 %%G --password1 %%H ^
  --host2 imap.side2.org --user2 %%I --password2 %%J ...

The ... have to be replaced by nothing or any imapsync option. Welcome in shell or batch programming !

You will find already written scripts at https://imapsync.lamiral.info/examples/

INSTALL
 Imapsync works under any Unix with Perl.

 Imapsync works under most Windows (2000, XP, Vista, Seven, Eight, Ten
 and all Server releases 2000, 2003, 2008 and R2, 2012 and R2, 2016)
 as a standalone binary software called imapsync.exe,
 usually launched from a batch file in order to avoid always typing
 the options.

 Imapsync works under OS X as a standalone binary
 software called imapsync_bin_Darwin

 Purchase latest imapsync at
 https://imapsync.lamiral.info/

 You'll receive a link to a compressed tarball called imapsync-x.xx.tgz
 where x.xx is the version number. Untar the tarball where
 you want (on Unix):

  tar xzvf  imapsync-x.xx.tgz

 Go into the directory imapsync-x.xx and read the INSTALL file.
 As mentioned at https://imapsync.lamiral.info/#install
 the INSTALL file can also be found at
 https://imapsync.lamiral.info/INSTALL.d/INSTALL.ANY.txt
 It is now split in several files for each system
 https://imapsync.lamiral.info/INSTALL.d/

CONFIGURATION
There is no specific configuration file for imapsync, everything is specified by the command line parameters and the default behavior.

HACKING
Feel free to hack imapsync as the NOLIMIT license permits it.

SIMILAR SOFTWARE
  See also https://imapsync.lamiral.info/S/external.shtml
  for a better up to date list.

Last updated and verified on Thu Apr 11, 2019.

  imapsync         : https://github.com/imapsync/imapsync
                     (this is an imapsync copy, sometimes delayed,
                     with --noreleasecheck by default since release 1.592, 2014/05/22)
  imap_tools       : https://web.archive.org/web/20161228145952/http://www.athensfbc.com/imap_tools/
                     The imap_tools code is now at
                     https://github.com/andrewnimmo/rick-sanders-imap-tools
  imaputils        : https://github.com/mtsatsenko/imaputils (very old imap_tools fork)
  Doveadm-Sync     : https://wiki2.dovecot.org/Tools/Doveadm/Sync ( Dovecot sync tool )
  davmail          : http://davmail.sourceforge.net/
  offlineimap      : http://offlineimap.org/
  mbsync           : http://isync.sourceforge.net/
  mailsync         : http://mailsync.sourceforge.net/
  mailutil         : http://www.washington.edu/imap/ part of the UW IMAP tookit.
  imaprepl         : https://bl0rg.net/software/ http://freecode.com/projects/imap-repl/
  imapcopy (Pascal): http://www.ardiehl.de/imapcopy/
  imapcopy (Java)  : https://code.google.com/archive/p/imapcopy/
  imapsize         : http://www.broobles.com/imapsize/
  migrationtool    : http://sourceforge.net/projects/migrationtool/
  imapmigrate      : http://sourceforge.net/projects/cyrus-utils/
  larch            : https://github.com/rgrove/larch (derived from wonko_imapsync, good at Gmail)
  wonko_imapsync   : http://wonko.com/article/554 (superseded by larch)
  pop2imap         : http://www.linux-france.org/prj/pop2imap/ (I wrote that too)
  exchange-away    : http://exchange-away.sourceforge.net/
  SyncBackPro      : http://www.2brightsparks.com/syncback/sbpro.html
  ImapSyncClient   : https://github.com/ridaamirini/ImapSyncClient
  MailStore        : https://www.mailstore.com/en/products/mailstore-home/
  mnIMAPSync       : https://github.com/manusa/mnIMAPSync
  imap-upload      : http://imap-upload.sourceforge.net/
                     (a tool for uploading a local mbox file to IMAP4 server)

HISTORY
I initially wrote imapsync in July 2001 because an enterprise, basystemes, paid me to install a new imap server without losing huge old mailboxes located in a far away remote imap server, accessible by an often broken low-bandwidth ISDN link.

I had to verify every mailbox was well transferred, all folders, all messages, without wasting bandwidth or creating duplicates upon resyncs. The design was made with the beautiful rsync command in mind.

Imapsync started its life as a patch of the copy_folder.pl script. The script copy_folder.pl comes from the Mail-IMAPClient-2.1.3 perl module tarball source (more precisely in the examples/ directory of the Mail-IMAPClient tarball).

So many happened since then that I wonder if it remains any lines of the original copy_folder.pl in imapsync source code.