On Monday, June 15, 2009 at 16:49 CEST,
"Terry L. Inzauro" <tinza...@ha-solutions.net> wrote:
> I operate a backup mx for one of my customers. In doing so, I have run
> into an issue where I must accept all email regardless of weather or
> not the messages is destined for a valid email account in my customers
> email system (which is MS Exchange 2003).
>
> I thought about asking my customer is they would export a list of
> email addresses for which they want backup MX service for so I can
> place that in a relay_recipient_map, but that process requires ongoing
> admin time and might not appeal to them.
>
> The majority of the junk mail I am seeing is in the form of From:
> u...@domain and RCPT: u...@domain which is obviously forged. Would a
> header_check be the way to go here in order to match and discard the
> junk mail in this case? If so, what would the pcre check look like?
header_checks cannot be used like that. Besides, it wouldn't solve the
backscatter problem.
Either obtain a full recipient list for use with relay_recipient_maps,
use recipient address verification, or don't be a backup MX.
--
Magnus Bäck
mag...@dsek.lth.se
