maildrop notes This is about Postfix 2.2.10 and maildrop 2.0.4 on EL4. Postfix is configured with no Unix users, just lots of virtual domains and virtual users, e.g. main.cf: {code:none} #/etc/postfix/main.cf ... virtual_alias_maps = hash:/etc/postfix/virtual virtrual_mailbox_domains = firstname_lastname.com firstname2_lastname2.com firstname3_lastname3.com virtual_mailbox_base = /var/mail/vhosts virtual_mailbox_maps = hash:/etc/postfix/vmailbox ... {code} {code:none} #/etc/postfix/virtual #there are some mail aliases here which forward to another MX #because the users are not Unix users so they don't have a $HOME/.forward user1@firstname_lastname.com foo@another.domain.tld user2@firstname_lastname.com blah@yet.another.domain.tld #this is also different from /etc/aliases which is only for local aliases {code} {code:none} #/etc/postfix/vmailbox firstname@firstname_lastname.com name1/Maildir firstname2@firstname2_lastname.com name2/Maildir lastname@firstname_lastname.com name1/Maildir ... #this maps the various e-mail addresses to a mailbox {code} Now we want to be able to use maildrop to do some filtering on the mails on this family server. This HOWTO claims to do it: http://www.postfix.org/MAILDROP_README.html Simply install maildrop and add these two lines to main.cf: {code:none} maildrop_destination_recipient_limit = 1 virtual_transport = maildrop {code} This will use maildrop as the delivery agent for all virtual addresses, but not for any mail related to local Unix accounts, and it tells Postfix that maildrop only processes one message at a time. You also need to add the appropriate pipe command in master.cf as in the howto. 1 Too bad it doesn't work! /etc/init.d/postfix reload {code:none} Aug 5 21:51:39 hostname postfix/pipe[3088]: 23066246EE: to=<postmaster@hostname>, relay=maildrop, delay=0, status=bounced (user unknown. Command output: Invalid user specified. ) {code} What now? Google to the rescue: http://www.security-express.com/archives/postfix/2004-04/1411.html It seems we "merely" need to configure maildrop to understand the mappings in the virtual_mailbox_maps file, otherwise it doesn't know where to actually deliver the mail. There's a bunch of references on the web to MySQL or LDAP based lookups, or "makeuserdb" all of which seem irrelevant for us. 1 Possibly useful links Example maildroprc: http://gentoo-wiki.com/Maildrop_configuration Official latest docs: http://www.courier-mta.org/maildrop/maildrop.html Example maildroprc: http://www.vanadac.com/~dajhorn/projects/fsavp/maildroprc.txt 1 Some maildrop tricks something about env vars: http://osdir.com/ml/mail.maildrop/2004-01/msg00038.html tips from 1998: http://www.courier-mta.org/maildrop/maildroptips.html 1 Here's a similar issue http://sourceforge.net/mailarchive/forum.php?thread_name=468539B5.20004%40interfree.it&forum_name=courier-maildrop 2007-08-06 00:20:14.0 2007-08-05 23:15:34.0