On 2012-01-13 4:48 AM, DTNX/NGMX Postmaster <postmas...@dtnx.net> wrote:
We use a modified version as a HELO blacklist. This avoids the false
positives we saw while testing it as a reverse DNS restriction but,
because the use of the reverse hostname as the HELO string is a
common pattern in spam attempts from compromised hosts, it's still
very effective.
It's a 'check_helo_access' restriction in our
'smtpd_recipient_restrictions', and sits right before our RBL checks,
where it has blocked 17235 attempts so far this year, with zero false
positives since we started using it, in November somewhere.
Interesting... can you provide specific details on what you mean by
'modified version'?
I'm always looking for a safe (fp free) native postfix way to increase
blocks before RBL checks...
Thanks,
--
Best regards,
Charles
