Re: [exim] Fixing RDNS Instructions

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Author: Andrew - Supernews
Date:  
To: exim-users
Subject: Re: [exim] Fixing RDNS Instructions
>>>>> "Renaud" == Renaud Allard <renaud@???> writes:

Renaud> You should maybe add some info about how the HELO of a
Renaud> mailserver should be resolved.

Renaud> So the best way would be HELO == A == PTR

HELO == A == PTR is best _only_ if the PTR record value is not generic.

If you control the PTR record, then set it to a non-generic value
(mail.example.com rather than ip-192-0-2-25.example.com).

If you _don't_ control the PTR record, and the upstream has it set to
a generic value, then having the HELO == A being a non-generic name is more
important than HELO == PTR.

(There are a handful of loons who will block you for HELO != PTR, but these
are vastly outnumbered by the people who will (directly or indirectly) block
you for HELO == generic name. A smaller number of people will block you for
PTR == generic name, but you either have to put up with that or get control
of your PTR records, in which case see above.)

(Another myth that seems widespread is the HELO == MAIL FROM domain
one, which is completely spurious. I would love to know how this one
got started.)

--
Andrew, Supernews
http://www.supernews.com