On 10/10/2010 19:41, Matthias-Christian Ott wrote:
>> I recently got notified from a mailing list which is mangaged with
>> ezmlm that E-Mails could not be delivered because my mail server
>> rejected them. It turned out that the SMTP server or ezmlm itself
>> rewrote the recipient of the envelope from bob@??? to
>> bob@???, because example.com was a CNAME for b.example.com.
>>
>> Is such rewriting compliant with any standard (according to the
>> rejectlog no other E-Mails got rejected for this reason)?
>
> As more E-Mails come in, it seems very likely that some SMTP servers
> got confused by the CNAME and as far as I can tell from the logs
> didn't even try to deliver the E-Mails to my server.
If your MX record is pointing at a CNAME, then your DNS is broken. MX
records are not allowed to point at CNAMEs, they're only allowed to
point at A records.
--
Mike Cardwell - Perl/Java/Web developer, Linux admin, Email admin
Read my tech Blog - https://secure.grepular.com/
Follow me on Twitter - http://twitter.com/mickeyc
Hire me - http://cardwellit.com/ http://uk.linkedin.com/in/mikecardwell
