Hello list,
I am not quite sure whether this is a questions for Dovecot or Postfix. I have set up, virtual hosting for one domain (for test purposes) using a passwd-file as passdb and a static userdb (see dovecot -n at the end) along with Postfix in a manner described in [1], i.e. a non-Postfix mail store. Other than that I also do hosting for the canonical domain which is for users with a regular Unix account on the system (looked up via PAM)
The virtual domain shall be "example.org", with two users "alice@example.org" and "bob@example.org".
But today I received spam mail (which was correctly identified as such by amavisd-new) for "info@example.org" and "sales@example.org", two recipient addresses that do not exist. According to [1] "it's left up to the non-Postfix delivery agent to reject non-existent recipients from local submission or from local alias expansion."
How to deal with such a situation?
The sender address was clearly forged so returning a failed delivery message is pointless. The messages are now hanging around in the queue with a status of "deferred: temporary failure".
The logs show:
dovecot: auth(default): passwd(info@exmaple.org): unknown user dovecot: auth(default): passwd-file(info@mexample.org): unknown user dovecot: auth(default): static(info@example.org): passdb doesn't support lookups, can't verify user's existence
postfix/pipe[25328]: C7EA18BC0B5: to=info@exmaple.org, relay=dovecot, delay=1.4, delays=0.07/0.02/0/1.3, dsn=4.3.0, status=deferred (temporary failure)
The dovecot relay is defined in /etc/postfix/master.cf:
dovecot unix - n n - - pipe flags=DRhu user=vmail:vmail argv=/usr/local/libexec/dovecot/deliver -f ${sender} -d ${recipient}
The question, once again, is: what to do in such a situation? A catch-all address could be set up, but to what end? It would just catch a lot of spam over time. What is the correct way to deal with this?
More importantly: is there even anything Dovecot could (or should) do?
Thanks in advance,
Andreas
[1] http://www.postfix.org/VIRTUAL_README.html#in_virtual_other
# 1.0.10: /usr/local/etc/dovecot.conf base_dir: /var/run/dovecot/ protocols: imap imaps pop3 pop3s managesieve listen(default): * listen(imap): * listen(pop3): * listen(managesieve): *:2000 ssl_cert_file: /path/to/ssl_cert ssl_key_file: /path/to/private_key login_dir: /var/run/dovecot//login login_executable(default): /usr/local/libexec/dovecot/imap-login login_executable(imap): /usr/local/libexec/dovecot/imap-login login_executable(pop3): /usr/local/libexec/dovecot/pop3-login login_executable(managesieve): /usr/local/libexec/dovecot/managesieve-login mail_extra_groups: mail mail_location: maildir:~/Maildir maildir_copy_with_hardlinks: yes mail_executable(default): /usr/local/libexec/dovecot/imap mail_executable(imap): /usr/local/libexec/dovecot/imap mail_executable(pop3): /usr/local/libexec/dovecot/pop3 mail_executable(managesieve): /usr/local/libexec/dovecot/managesieve mail_plugin_dir(default): /usr/local/lib/dovecot/imap mail_plugin_dir(imap): /usr/local/lib/dovecot/imap mail_plugin_dir(pop3): /usr/local/lib/dovecot/pop3 mail_plugin_dir(managesieve): /usr/local/lib/dovecot/managesieve imap_client_workarounds(default): outlook-idle delay-newmail tb-extra-mailbox-sep imap_client_workarounds(imap): outlook-idle delay-newmail tb-extra-mailbox-sep imap_client_workarounds(pop3): outlook-idle imap_client_workarounds(managesieve): outlook-idle pop3_uidl_format(default): pop3_uidl_format(imap): pop3_uidl_format(pop3): %08Xu%08Xv pop3_uidl_format(managesieve): sieve_storage(default): sieve_storage(imap): sieve_storage(pop3): sieve_storage(managesieve): ~/sieve sieve(default): sieve(imap): sieve(pop3): sieve(managesieve): ~/.dovecot.sieve namespace: type: public separator: / prefix: Public/ location: maildir:/var/mail/public:CONTROL=~/Maildir/control/public:INDEX=~/Maildir/index/public namespace: type: private separator: / inbox: yes auth default: mechanisms: plain login verbose: yes passdb: driver: passwd-file args: /etc/dovecot/passwd passdb: driver: pam userdb: driver: passwd userdb: driver: static args: uid=vmail gid=vmail home=/home/vmail/%d/%u socket: type: listen client: path: /var/spool/postfix/private/auth mode: 432 user: postfix group: postfix master: path: /var/run/dovecot/auth-master mode: 432 user: vmail group: vmail
Andreas "daff" Ntaflos Vienna, Austria
GPG Fingerprint: 6234 2E8E 5C81 C6CB E5EC 7E65 397C E2A8 090C A9B4