David Wells:
> Hi!
>
> I have a postfix-3.3.2 installation (installed from source on slackware
> 14.2 from the slackbuilds package) that does rbl checks in the
> smtpd_recipient_restrictions section. I have been seeing an increasing
> amount of spam coming in so I added more reject_rbl_client instances
> listing more and more rbl servers. However I still am seeing large
> ammounts of spam getting through and I have checked several mails that
> have come in using http://multirbl.valli.org/ and the servers from which
> they arrive are listed in at least one of these rbl checks, most times
> in more than one. Is there a way to debug why these mails are getting
> through even though they come from an rbl blacklisted server?
Check the time TIME STAMPS in your logs.
Spammers are not immediately listed. There is a delay during which
a DNSBL will not list a spammer's IP address. By the time that you
do a maual DNSBL lookup, the DNSBL may have been updated.
Another possible reason is that DNS lookup result times out or fails
for other reasons; Postfix will log such problems.
Wietse
>
>
