[Mimedefang] Multiple servers scanning mail

[Conrad J. Koch]

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.

Hope that all makes sense - I've had a lot of coffee today... :)

So, basically I have a multi-part question:

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?

Sorry for asking what's probably been answered many times before, but 
I've been flat-out here and haven't had a lot of time to go a-Googling 
for the answer in archives (etc..).

Thanks in advance!

-Conrad