Slow access to RBLs?

[Magnus Stenman]

I've noticed that when a DNSRBL's NS records cannot be looked up , all
sorts of weird sendmail delays can occur.  Bloody spammers DoSing....


I've seen it with osirusoft and spamcop.

I never had time to investigate, I just temporarily disabled those
DNSRBL sources.


/m

Stanier, Alan M wrote:

> We are running MailScanner 4.23-11 under RedHat-9
>
> Yesterday email starting running extremely slowly, with messages accumulating
> in the Incoming Queue Directory
>
> Messages in /var/adm/maillog showed problems with RBL checking ...
>
> Oct  8 09:01:20 serlinux15 MailScanner[18710]: RBL Check relays.ordb.org timed out and was killed, consecutive failure 4 of 7
> Oct  8 09:01:45 serlinux15 MailScanner[18670]: RBL Check MAPS-RBL+ timed out and was killed, consecutive failure 1 of 7
>
> I disabled RBL checking, and email started running at full speed again.
>
> It seems infeasible that all the RBLs we check should have developed problems
> simultaneously, so the problem is presumably local, but I can't think where.
> The network team here assure me they have made no changes which might have such
> an affect.
>
> Does anyone have any suggestion?
>
> --------
> Alan Stanier
> Essex University Information Systems Services
> Systems Group