[Mimedefang] Multiple servers scanning mail

[Joseph Brennan]

--On Wednesday, July 14, 2004 12:05 PM -0400 "Conrad J. Koch" 
<ckoch at dc.alphatech.com> wrote:

> Hello,
>
> We've got a setup where certain mail goes to our main corporate mail
> server ("server1": Solaris 8, sendmail 8.12.10, MD 2.40, SA ?) and gets
> scanned by MD/SA and, if appropriate based on the recipient, gets shunted
> to another mail server ("server2": Solaris 9, sendmail 8.12.11, MD 2.4.2,
> SA 2.63) where it is again scanned by MD/SA.
>
> If server1 detects spam, it adds the appropriate X-Spam-Score header and
> sends the mail off to server 2 when needed. If server2 does not detect
> the same mail as spam, it appears to strip the X-Spam-Score header. The
> users' mail clients are configured to filter based on this header so
> users popping mail from server2 aren't able to accurately  filter based
> on server1's detection when server2 "misses". I don't want to have
> server2 bypass spam checking when server1 has already done so, since
> server1 may miss spam that server2 would catch.
>
...
> How can I prevent server2 from stripping the X-Spam-Score header? And/Or,
> can anyone suggest other alternatives - other than consolidating into a
> single server?


My first reaction is that server2 could be set up to accept incoming
mail only from server1 (one way is access.db), and you could avoid
the double-filtering and get more out of the hardware.  Can you pitch
this to someone who cares about the budget :-)

But anyway... whether Mimedefang writes over X-Spam-Score is totally
under your control in filter.  There must be something like this...

            else {
                # Delete any existing X-Spam-Score header?
                action_delete_header("X-Spam-Score");

...so comment it out.  But you might want to keep it with a condition
on it, like if $RelayAddr is not server1 then action_delete_header.

Joseph Brennan
Academic Technologies Group, Academic Information Systems (AcIS)
Columbia University in the City of New York