Blacklist outgouing mail

Discussion in 'General' started by MrM, Aug 24, 2009.

  1. MrM

    MrM New Member

    Hi,

    A major Slovenian free e-mail provider has recently gone bust. As a result, thousands of outgoing e-mails are being deferred in our server's mail logs, as some of the hosted sites still try to send e-mail to these addresses.

    Is there a way to tell postfix (through ISPConfig if possible) to completely ignore any e-mail being sent out, whose recipient belongs to a certain domain? Postfix should not try to send such messages and if possible, not even log the attempt.

    I tried adding a record to "Email > Global Filters > Postfix Blacklist" with "@offending-domain.tld" as Blacklist Address and Recipient as Type. This doesn't seem to have the desired effect though.
     
  2. till

    till Super Moderator Staff Member ISPConfig Developer

    Try this:

    add a email route / (transport) in ispconfig with:

    domain: offending-domain.tld
    type: error
    destination: This email address does not exist anymore.
     
  3. MrM

    MrM New Member

    Thanks, till. It worked. The messages no longer go to the queue. However, quite a lot of entries are still added to the logs for a single message:
    Code:
    Aug 24 20:32:34 prod postfix/pickup[8518]: 4D0F51CF1F2: uid=0 from=<root>
    Aug 24 20:32:34 prod postfix/cleanup[8551]: 4D0F51CF1F2: message-id=<20090824183234.4D0F51CF1F2@hostname.server-domain.tld>
    Aug 24 20:32:34 prod postfix/qmgr[8520]: 4D0F51CF1F2: from=<root@hostname.server-domain.tld>, size=316, nrcpt=1 (queue active)
    Aug 24 20:32:34 prod postfix/error[8554]: 4D0F51CF1F2: to=<mailbox@offending-domain.tld>, relay=none, delay=0.12, delays=0.09/0.01/0/0.01, dsn=5.0.0, status=bounced ([This email address does not exist anymore.])
    Aug 24 20:32:34 prod postfix/cleanup[8551]: 5C5851CF1F3: message-id=<20090824183234.5C5851CF1F3@hostname.server-domain.tld>
    Aug 24 20:32:34 prod postfix/qmgr[8520]: 5C5851CF1F3: from=<>, size=2025, nrcpt=1 (queue active)
    Aug 24 20:32:34 prod postfix/bounce[8555]: 4D0F51CF1F2: sender non-delivery notification: 5C5851CF1F3
    Aug 24 20:32:34 prod postfix/qmgr[8520]: 4D0F51CF1F2: removed
    Aug 24 20:32:34 prod postfix/cleanup[8551]: 654221CF1EA: message-id=<20090824183234.5C5851CF1F3@hostname.server-domain.tld>
    Aug 24 20:32:34 prod postfix/qmgr[8520]: 654221CF1EA: from=<>, size=2162, nrcpt=1 (queue active)
    Aug 24 20:32:34 prod postfix/local[8556]: 5C5851CF1F3: to=<root@hostname.server-domain.tld>, relay=local, delay=0.04, delays=0.02/0.01/0/0.01, dsn=2.0.0, status=sent (forwarded as 654221CF1EA)
    Aug 24 20:32:34 prod postfix/qmgr[8520]: 5C5851CF1F3: removed
    It looks like the message gets bounced now. Is it possible to send it to /dev/null instead? It's not a big problem if this is not possible. Getting all those messages out of the queue was my first priority. Completely ignoring them would be a better option, but as I said, not strictly necessary.
     
  4. bajodel

    bajodel New Member

    Take a look at postfix restrictions parameters .. expecially at "reject_unknown_recipient_domain"

    Requirements: the dns (mx or a) records of that provider domain must no longer exist.

    If it suits your needs you will able ( modding your /etc/postfix/main.cf ) to do the trick in a better way ..you can avoid to receive the entire messages before dropping them (blocking them at smtp first dialog level) .. saving bandwith :)

    Bye..

    bajodel.
     
  5. MrM

    MrM New Member

    In this case, the MX record still exists, but the SMTP server is no longer responding, so I guess this option will not help.

    The provider in question is actually email.si:
    Code:
    $ dig email.si IN MX
    ...
    ;; ANSWER SECTION:
    email.si.		3421	IN	MX	20 mx5.email.si.
    
    
    $ telnet mx5.email.si 25
    Trying 81.24.97.24...
    telnet: Unable to connect to remote host: Connection timed out
    Heh, bandwidth actually isn't a problem in this case, since the postfix server is only being used by the websites running on the same server. I was only hoping to get rid of the log entries and bounced messages, but as I said before, it's just a minor annoyance, not a serious issue. The bulk of the problem has already been solved with till's suggestion.
     
  6. bajodel

    bajodel New Member

    Ok.. it's not so clean ..but you can 'cook' fake ones :) configuring that domain in your dns with a TEXT record only.
    Postfix will look at MX and A records -> not present -> reject

    Ok.. maybe it is not a problem for you, but it could be usefull for others..

    Bye..

    bajodel.
     
  7. MrM

    MrM New Member

    I'll do that. Thanks for the idea. ;)


    You're right. Sorry if I sounded ungrateful.

    Thanks, till and bajodel, for helping out.
     

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