@lbutlr:
> I get a few thousand messages like this every day:
>
> mail postfix/smtpd[59689]: warning: hostname sa0877.azar-a.net does not =
> resolve to address 91.219.236.126
>
> And while I assume that these are all just spammers, it looks like the =
> connection continues to get processed and (at least in the few I've
> checked) eventually gets rejected by an RBL check in postscreen.
The warning is logged, so that you know why the client is logged
as "unknown", and why access rules based on domain names will not
work as expected.
> This processing takes a while, and several connections are made, so is =
> there anything I should consider doing to speed this reection process =
> up? Or shoudl I just ignore this as =E2=80=9Cworking as intended=E2=80=9D?=
> Here is one connecton from earlier today which appears to have made a =
> total of 6 connections (4 CONNECT and 2 connect) over the course of =
> about 90 seconds.
If you could speed up the remote DNS server, that would be best
(yes, that is a joke). But it does illustrate why postscreen will
never to client hostname lookups.
> Jul 14 08:12:35 mail postfix/postscreen[19509]: CONNECT from =
> [104.171.171.62]:47075 to [65.121.55.42]:25
> Jul 14 08:12:39 mail postfix/postscreen[19509]: PASS NEW =
> [104.171.171.62]:47075
> Jul 14 08:12:54 mail postfix/smtpd[23615]: warning: hostname =
> rheocrat62.vwhconsulting.com does not resolve to address 104.171.171.62: =
> hostname nor servname provided, or not known
With this particular domain, any lookup for vwhconsulting.com fails
with SERVFAIL after several seconds. There are many poorly-managed
domains.
Wietse
