[Mimedefang] Blocking e-mail where the To does not match the envelope To

[Sidney Markowitz]

Jon Kenoyer <jonk at otsi.com> asked:
> Could I add a rule to discard e-mails where the To does not match the
> actual recipients.  If so could someone post a quick sample?
> Are there cases where this could block legitimate e-mails?

Here are some headers from the above mail I received from you:

  From: "Jon Kenoyer" <jonk at otsi.com>
  To: <mimedefang at lists.roaringpenguin.com>

My MTA doesn't insert the envelope recipient in most cases, but I can assure
you that it could not have been mimedefang at lists.roaringpenguin.com

In any case in which you are on a Bcc list, which is typically the case in a
mailing list, your address will not show up in the To or Cc headers.

Anyway, if you are interested in rules for detecting spam I suggest that you
just download SpamAssassin. It already works with MimeDefang and benefits
from lots of people putting together hundreds of rules that can come up with
an aggregate score to filter spam from nonspam.

 -- sidney