More Spam on Backup MX Hosts

[mikea]

On Wed, Jun 18, 2003 at 03:41:25PM -0500, Mike Kercher wrote:
> Yes...it's a common tactic by a lot of Spamware to hit lower priority MX
> records first in hopes that they will be less secure than the primaries.

Much discussed on the SPAM-L list, and on a couple of private lists
dealing with spam and responses to it. One countermeasure is to put
your highest-priority MX host in as your lowest-priority MX as well.

I've been told that some RFC says this is a bad thing, but I haven't
been told _which_, and it does appear to work somewhat.

Eventually, of course, the spammers will pick MX hosts at random
from the list -- if they aren't doing it already.

--
Mike Andrews
mikea at mikea.ath.cx
Tired old sysadmin since 1964