Well, after actually looking at it a bit further, it would appear I over-simplified the issue, but nonetheless, it shouldn't be a problem. Some editing of your .mc file and the mailertable are also necessary.
Ah, yes...
A point in the right direction is here:
<http://groups.google.com/ groups?oi=djq&as_umsgid=%3C8fi50l%24jqe%241%40news.du.uab.ericsson.se%3E >
and here (the thread leading up to the previous link):
<http://www.softpanorama.org/Mail/procmail_from_sendmail.shtml>
I think I was going down this same path at one time - never found the pot of gold at the end though....
Well, I have to admit sheepishly that I haven't actually done it. We currently do our spam filtering on the actual mail server, not the relays (we don't have that much volume). But according to the links above, it is possible, and people have done it.
Bottom line, the devil is in the details, isn't it?
Joe
