[Mimedefang] filter config question

[Rich West]

A while back I configured mimedefang to *not* scan email the is destined 
to the hosted mailing lists.

However, I just noticed that it *is* scanning email *from* the lists out 
to the list members.  Interestingly enough, this is causing some problems..

Is there an easy way within the filter to determine what host the 
message is originating from (I only want it to bypass if the originating 
host is the maillist server (in this case, localhost))?

-Rich