Setting Up POP Before SMTP

Support knowledgebase (rsimai_imap_dracd)
Applies to

eMail Server: Version 3

Situation

You want to set up POP before SMTP to enable relay access after the authentication.

Procedure

The required dracd is already installed and running on your system.
Please proceed as follows:
  1. Edit the file /etc/postfix/main.cf and change the line
    smtpd_recipient_restrictions= ldap:ldapmailenab, permit_tls_clientcerts, permit_sasl_authenticated, permit_mynetworks, check_relay_domains
    to
    smtpd_recipient_restrictions= ldap:ldapmailenab, permit_tls_clientcerts, permit_sasl_authenticated, permit_mynetworks, check_client_access btree:/etc/postfix/dracd, check_relay_domains

    Please do not use line wrapping! However, if you want to use line wrapping, make sure the subsequent lines do not start at the beginning of the line. You can do this by e.g. inserting a blank.

  2. Edit the file /etc/imapd.conf and change the line
    dracinterval: 0
    to
    dracinterval: 4
  3. The time interval is defined with DRACD_RELAYTIME="5" (in minutes) in the file /etc/rc.config. If necessary, this value can be modified.

  4. Restart the POP/IMAP service: rccyrus restart

  5. Restart the Postfix service: rcpostfix restart

  6. If you have modified DRACD_RELAYTIME, restart dracd, too: rcdracd restart

Description

If your clients are not located in the same network as the eMail Server, the eMail Server will first deny mail relaying ('relay access denied'). This restriction protects the eMail Server from abuse (open relay) and should not be removed entirely.
Following a successful authentication via POP or IMAP, dracd saves the sender's IP in a database. For the period determined by DRACD_RELAYTIME, the eMail Server grants relay access to the sender with this IP. Afterwards, a new authentication is required. POP clients can do this by prompting a mail retrieval. For IMAP clients, dracinterval can be used to prompt dracd to look for an open connection so that DRACD_RELAYTIME does not time out.
For a detailed description of DRAC check the URL:
http://mail.cc.umanitoba.ca/drac
Keywords: IMAP3, DRACD, RELAY, ACCESS, DENIED
Categories: SuSE Linux IMAP Server
SDB-rsimai_imap_dracd, Copyright SuSE Linux AG, Nürnberg, Germany - Version: 05. Dez 2001
SuSE Linux AG - Last generated: 06. Dez 2001 by ip (sdb_gen 1.40.0)