[Mimedefang] SURBL effectiveness and domain turnaround time

[David F. Skoll]

On Thu, 9 Sep 2004, Jeff Rife wrote:

> I'll have to
> see if I can set up my cache so that negative responses from specific
> domains/servers have a different TTL than "general" ones.

This is set in the SOA record of the domain, which for sc.surbl.org
is 15 minutes.  You can, of course, override this in your BIND
configuration, but maybe you shouldn't.

> > DNS lookups are pretty cheap -- one UDP packet out and one UDP packet back
> > in.

> A couple of delays in response can just kill throughput on sendmail,
> though.

If you handle enough mail for that to be a concern, you're probably
eligible for an rsync zone transfer.

Regards,

David.