SpanAssassin has flagging internal mail between our users as spam, rather than adding our IPs or domains to SpamAssassin's whitelists I thought it would be best to skip SA and ClamAV all together for mail originating from our internal users. I have googled a bit but have found no way to do this but I'm pretty sure it would be possible. We have PostFix + Procmail setup on one server to handle all the mail. I'm guessing procmail would be the service that would check to see if mail is internal and then send it to spam assassin if it's not. Here's my current procmailrc:
DROPPRIVS=yes
:0cw
| /etc/webmin/virtual-server/clam-wrapper.pl /usr/bin/clamscan
VIRUSMODE=1
:0e
/dev/null
VIRUSMODE=0
:0fw
| /usr/bin/spamc
SPAMMODE=1
:0
* ^X-Spam-Status: Yes
$HOME/Maildir/.spam/
SPAMMODE=0
Let me know of any ideas you have. Thanks.