MX Record question...

[Barry Margolin]

In article <9jafa6$55e at pub3.rc.vix.com>, Dave  <meliorasf at yahoo.com> wrote:
>Question:
>
>Can I also have an mx record in that same zone file for
>"mail.domain.com?" The reason I want to do this is that occasionally
>people send mail to "user at mail.domain.com" instead of
>"user at domain.com."  When they do this, they get the following error in
>a returned email:
>
>
>>Failed to deliver your message to user at mail.domain.com:
>>SMTP: DNS Routing Loop
>>The Domain Name System record for 'domain.com.'
>>points back to 'domain.com'
>
>
>Anybody know if I can set up the 2nd MX?  Or do I need a whole separate
>zone file to do this?

The above error is not due to a missing MX record.  If there's no MX record
for a hostname, the mail will be delivered directly to the host (MX records
are like the post office's mail forwarding instructions).

The error you're getting is because when the mail is being delivered to
your server, it doesn't know what to do with it.  It's not in its list of
locally-deliverable addresses, but it can't find an MX record that says
where to forward it to.  If the server is running sendmail, you need to add
"mail.domain.com" to the sendmail.cw file or the Cw line in sendmail.conf.

-- 
Barry Margolin, barmar at genuity.net
Genuity, Woburn, MA
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