limiting data acl scan

I'm trying to determine how to limit the data acl
scan (ie spam scanning) to only email that is
destined for local delivery.

The situation is that I have a number of domains for
which I do MX secondary. All of these domains do their
own spam / virus scanning.  So its effort (ie cpu cycles)
that is in essence wasted for my server to scan email
that is going to be forwarded to the these domains.
Unfortunately, trying to check for the domain using
an accept domains = +local_domains isn't allowed in
the data acl.  So I need some other mechanism for limiting
the scan.

For what its worth, once the mail is scanned and is for
local delivery, I have a very nice router setup that
checks for the local domain and places the spam into a
separate mail box for each end user.  If anyone is interested,
I would be glad to post that solution to the list.

Thanks.


Andy Rundquist
(one of the original smail-3 gang)