--- On Thu, 5/2/13, Benoit Panizzon <[email protected]> wrote: > Goal: Minimize Backscatter. > > Problem: Customers do forward their email address to some other > addresses which are have full quota or just any other problems. > > Solution: Do this whole Aliasing and Forward-Address handling with > MIMEDefang. As the local email address doing the forward is know > to be good (or not, ....
I actually do this with sendmail's M4 rulesets and a pair of external maps, and I only rewrite the envelope sender field if SPF is detected in use for the sender domain. Otherwise, such a rewrite is unnecessary. The rewriting map is a small program that generates the new field value and stores the old and new values into the second map (which is a simple text map) for the possible event of a reply (i.e. a DSN from a subsequent server in the event it's forwarded again). I expire entries after a week so that they can't be used to spam a sender at a later date. _______________________________________________ NOTE: If there is a disclaimer or other legal boilerplate in the above message, it is NULL AND VOID. You may ignore it. Visit http://www.mimedefang.org and http://www.roaringpenguin.com MIMEDefang mailing list [email protected] http://lists.roaringpenguin.com/mailman/listinfo/mimedefang
