Quite a few users are forwarding their mail to either yahoo or gmail, which is causing a lot of trouble because both services see spam being forwarded and blacklist the sending server (me). Gmail at least seems to calm down after a little while, but delays on some mail can be many hours.
These are users who are setting their own forwarding up via postfixadmin and getting forwarded by postfix based on the mysql lookup in proxy:mysql:/etc/postfix/mysql_virtual_alias_maps.cf, so the messages aren’t getting filtered at all (beyond what postscreen can do, of course). Is there anything that I can do about this on my end? Someway I can at least run spamassassin over the mail so I can not forward obvious spam? And if I AM forwarding obvious spam its at least marked as such by SA which might help. The gmail issues are mailq entries that look like this: D210621494D 12700 Tue Feb 3 21:30:55 n...@dontyoudropthat.com (host alt1.gmail-smtp-in.l.google.com[74.125.22.26] said: 421-4.7.0 [75.148.37.66 15] Our system has detected an unusual rate of 421-4.7.0 unsolicited mail originating from your IP address. To protect our 421-4.7.0 users from spam, mail sent from your IP address has been temporarily 421-4.7.0 rate limited. Please visit 421-4.7.0 http://www.google.com/mail/help/bulk_mail.html to review our Bulk 421 4.7.0 Email Senders Guidelines. z39si14220069gz.97 - gsmtp (in reply to end of DATA command)) That message eventually delivered at 03:09 today. Now, in this case it looks like it was probably spam and so the delay doesn’t matter, but sometimes the mail that is delayed is not spam. The only thing I can say at this point is “Google is delaying your mail” which is true, but not very useful. -- There is a road, no simple highway, between the dawn and the dark of night