cname replace in mail address? [off-topic] (Re: Attn Ronald Klop)

Doug Barton dougb at
Fri Aug 27 17:24:46 UTC 2010

On 08/27/2010 01:03 AM, Ronald Klop wrote:
> offtopic, but why do some mailers replace a CNAME in a mail-address?
> root at sheeva2:/var/vmail# host
> A
> It is not the first time that I'm bitten by this, but I never understood
> it.

You've already received all the right answers but I figured I'd respond 
too since this is my area. Given that is a CNAME, and that 
the target hostname ( has no MX record, the fact that you 
receive any mail at all is a tribute to the robustness principle. :)

If you're going to receive mail at then you should really 
have an MX record for it. See for more 
information if you need more information or references to the standards. 
The simplest way to solve your mail delivery problem is to have the 
@hostname refer to a canonical host (I.e., with an A and/or AAAA record) 
which also has an MX record. If you insist on using the 
_best_ way to do that would be to duplicate those 2 records from By adding an MX to thuis you are more likely to get mail 
if is a CNAME to it, even though it's still not "right."




	Improve the effectiveness of your Internet presence with
	a domain name makeover!

	Computers are useless. They can only give you answers.
			-- Pablo Picasso

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