"Alan J. Flavell" <a.flavell@???> said, in message
Pine.LNX.4.62.0508220800080.27520@???:
>
> This might be well known, but we've noticed that spammers must be
> keeping lists of old MX entries, long after we've considered the
> associated email domains to be obsolete and have deleted the MX
> entries in the DNS.
I noticed similar a couple of years back. If I recall, it wasn't even the
MX records that were being cached, but the IPs they expanded to. At the
time, I idly wondered whether there would be anything to be gained in
changing the IPs of our external facing mail servers every year.
Never tried it out, I'm afraid, so I've no idea whether this would help
block spam...
Cheers,
Alun.
--
Alun Jones auj@???
Systems Support, (01970) 62 2494
Information Services,
University of Wales, Aberystwyth
