[Mimedefang] Net::DNS module for DNS lookups

[Joseph Brennan]

> These domains don't match ( 0x50a132cb.virnxx2.adsl-dhcp.tele.dk  is not
> FOR-2.com ). This seem to be very typical of many spam messages. If a
> message is From: friend at ibm.com then shouldn't it be arriving from some
> system at hostname.ibm.com ??


1. Vanity domains.

2. Mailing lists.

3. Travellers using hotel or cafe connections but setting From to
their usual address.

4. People with more than one account who use the From to direct
replies or show what role they are sending as.

Those are just the first legitimate cases I thought of.

Joseph Brennan          Columbia University in the City of New York
postmaster at columbia.edu                 Academic Technologies Group