Offence CNAME as MX??

[Simon Waters]

glen herrmannsfeldt wrote:
> 
> Theoretically, it works properly for the highest priority
> (lowest number) MX entry....

All modern mailers cope with this misconfiguration, it needs to
be correct for archaic sendmail versions only AFAIK, which
probably have major security flaw (Still no reason not to take
mail from them unless your totally paranoid).

The topic got done to death on the Postfix mailing list a while
back, despite Wietse saying Postfix "just calls the system
resolver", which is apparently all you have to do to cope with
it these days.

Still part of the reason for following standards is not only to
ensure that archaic versions of sendmail can e-mail you, but
that future modifications to the protocol can be cleanly
applied. Witness the importance of accepting TCP queries to
handling DNSSEC and other DNS protocol extensions sensibly.

Personally I think you'd need to be mad to run Sendmail these
days, let alone archaic versions, but that belongs in another
place.