[CentOS] OT: Strange Email Problem

Fri May 21 19:17:05 UTC 2010
Simon Billis <simon at houxou.com>

Susan Day sent a missive on 2010-05-21:

> Here are what the logs have to say:
> 
> @400000004bf6cfc4383bc65c delivery 6217: deferral:
> CNAME_lookup_failed_temporarily._(#4.4.3)/ @400000004bf6cfc4383c5eb4
> status: local 0/10 remote 0/255 @400000004bf6d51e34d61d8c starting 
> delivery 6218: msg 97881531 to remote suzieprogrammer at gmail.com 
> @400000004bf6d51e34d6449c status: local 0/10 remote 1/255
> @400000004bf6d51e37303e14 starting delivery 6219: msg 97881555 to 
> remote suzieprogrammer at gmail.com @400000004bf6d51e373078ac status: 
> local 0/10 remote 2/255 @400000004bf6d51e373143cc delivery 6218: deferral:
> CNAME_lookup_failed_temporarily._(#4.4.3)/ @400000004bf6d51e373241b4
> status: local 0/10 remote 1/255 @400000004bf6d51e37807d0c delivery 6219:
> deferral: CNAME_lookup_failed_temporarily._(#4.4.3)/
> @400000004bf6d51e3780bf74 status: local 0/10 remote 0/255
> 

Extract from:
http://nixforums.org/about25455-Help-Diagnosing-CNAME_lookup_failed_temporar
ily.html

"The likely cause of this is qmail's inability to handle large DNS
packets. The most-recommended solution is to install dnscache (from
djbdns), which trims off some unnecessary data and usually makes these
packets small enough for qmail to handle. The more correct solution
is to apply the "oversize DNS packets" patch to qmail (see
qmail.org). A hackish-but-fast solution is to choose one of
Earthlink's MXs, and put it in your smtproutes file. Not good
long-term, but it will get the mail out of your queue while you work
on a better solution."

I wouldn't put earthlinks mx in your smtproutes but you could put in you
isp's if you wanted to as a quick and dirty fix.

HTH

Simon.