[Mimedefang] Easy way to tell message is sent from local machine?

[Nate Carlson]

Is there an easy way to tell if a message is being sent from the local
machine out to someone else?

I'd like to set my mimedefang-filter up to only run SpamAssassin on
inbound messages; I really don't need to add Spam-Status: No headers to
outbound messages..

I suppose I could run through each of the local domains and see if the
sender is from one of them, but that wouldn't be good because spammers
sometimes leave a FQDN off so it gets spoofed to the local one (I know, I
can fix that in sendmail config), and because that'd mean maintaing a list
of local domains by hand.

-- 
Nate Carlson <natecars at real-time.com>   | Phone : (952)943-8700
http://www.real-time.com                | Fax   : (952)943-8500