Sample configurations

For when messages absolutely, positively have to be there within minutes.

Michael's .muttrc http://www.thatfleminggent.com/scripts/muttrc.mfleming

I recommend these DNS blocklists for use as an anti-spam protection on mailservers:

SpamHaus run by Steve Linford

Not Just a Blacklist

Distributed Sender Blocklist

smtpd_recipient_restrictions =
      permit_mynetworks,
      permit_sasl_authenticated,
      reject_unauth_destination,
      reject_invalid_hostname,
      reject_non_fqdn_sender,
      reject_non_fqdn_recipient,
      reject_unknown_sender_domain,
      check_sender_access mysql:/etc/postfix/access.cf,
      check_recipient_access hash:/etc/postfix/spamtraps,
      reject_unverified_recipient,
      reject_rbl_client zen.spamhaus.org,
      reject_rbl_client combined.njabl.org,
      reject_rbl_client list.dsbl.org,
      check_policy_service inet:127.0.0.1:10030,
      permit
smtpd_data_restrictions =
      reject_unauth_pipelining,
      permit

This is what I tossed together to allow my Courier IMAP + MySQL users to relay mail via my server (Postfix, naturally)

Put the following in /usr/lib/sasl2/smtpd.conf (adjust to suit):

pwcheck_method: auxprop
auxprop_plugin: sql  
mech_list: cram-md5 digest-md5
sql_engine: mysql
sql_hostnames: 127.0.0.1
sql_user: <mydbuser>
sql_passwd: <mydbpassword>
sql_database: <myvmaildb>
sql_select: SELECT clear FROM passwd WHERE id = '%u@%r' AND active = 1

Notes:

• Plaintext mechs like LOGIN and PLAIN aren't supported (Cyrus SASL plugin limitation).
• The sql_user only needs SELECT access to your Courier database.
• Adjust your sql_select to suit your virtual users schema.