RE: [exim] RFC's and DNS?

--On Monday, August 29, 2005 14:45 +0200 j2 <spamfilter2@???> wrote:

>> If you mean that you're trying to persuade them to set up REVERSE DNS
>
> No. Forward.
>
> Aug 29 10:34:58 statler exim: 2005-08-29 10:34:58 H=(nomsw01.avis.no)
> [80.203.197.34] rejected EHLO or HELO nomsw01.avis.no: Bad HELO:
> nomsw01.avis.no does not resolve
>
>
> Aug 29 10:34:58 statler last message repeated 3 times
>
>
> And thus,
>
> root@statler:/root/backup# host nomsw01.avis.no
> nomsw01.avis.no does not exist, try again


Ah - well, you'll want RFC821 section 3.5 or rfc2821 section 4.1.1.1, then.
You may have to argue that an unregistered domain name doesn't "help to
identify the client system".

On the other hand, many (most?) servers don't insist that the helo string
is a resolvable DNS name. It's quite a common error. We do insist that the
string is syntactically correct, but that still throws up a significant
number of errors - usually where a Windows client has an underscore.

However - you don't need to get the domain name registered, you just need
to have the mail server use a registered domain name.


--
Ian Eiloart
Servers Team
Sussex University ITS