[sclug] sendmail dns question.

[Simon Heywood]

On Thu, Jul 17, 2003 at 06:38:42PM +0000, Tom Dawes-Gamble wrote:
> Non-authoritative answer:
> triv.org.uk     mail exchanger = 90 mail.makyo.org.
> triv.org.uk     mail exchanger = 10 mail.triv.org.uk.
> triv.org.uk     mail exchanger = 80 jabog.tmdg.co.uk.

Okay, I think I may have worked this one out. You see, I changed the MX
records not too long before the server went down, swapping the priority
of mail.makyo.org and jabog.tmdg.co.uk. Probably out of some vague
belief that jabog has a more robust e-mail set-up than mail.makyo.org.

Now it's possible that, given the long TTL on my DNS records, and the
different caching times on the two backup mail servers, that both
thought that the other had a lower MX number for triv.org.uk. And had an
entertaining, yet short-lived, game of SMTP tennis.

Bugger.

While I'm on the subject, does anyone know if it's regarded as okay to
have CNAMES as the target of MX records?

S.