According to the FAQ:
2.5. How do I deal with ``CNAME lookup failed temporarily''? The log
showed that a message was deferred for this reason. Why is qmail doing
CNAME lookups, anyway?
Answer: The SMTP standard does not permit aliased hostnames, so qmail
has to do a CNAME lookup in DNS for every recipient host. If the
relevant DNS server is down, qmail defers the message. It will try again
soon.
-----Original Message-----
From: Sam [mailto:[EMAIL PROTECTED]]
Sent: Monday, April 19, 1999 11:02 AM
Cc: [EMAIL PROTECTED]
Subject: Re: aol.com bounces... our problem or their problem?
David A Galbraith CIRT writes:
>
>
> I'm getting a bunch of these in the logs...
>
> 921710651.349026 starting delivery 46759: msg 2501 to remote
[EMAIL PROTECTED]
> 921710651.378220 delivery 46759: deferral:
CNAME_lookup_failed_temporarily._(#4.4.3)/
>
> Is this something I should fix/can fix? or is this something aol has
> broken?
Most likely is that the large DNS response packet for the aol.com is
getting truncated, breaking Qmail.
Either hardcode one of AOL's mail servers into your smtprouters, or patch
Qmail to support larger DNS packets.
--
Sam
