Volume 50 of jgc's spam and antispam newsletter had a link for Nolisting, Poor Man's Greylisting at http://www.joreybump.com/code/howto/nolisting.html .
Basically, the premise is set an MX with a high preference pointing to a system that does not listen on port 25. Broken mailers would attempt to connect to it, fail, and not try a lower preference mail exchanger. A real mailer would fall back to a lower pref MX. When I was first starting with spam filtering, I had 2 server with unequal preferences and it seemed that more garbage would head to the lower preference exchanger, possibly thinking ti was an offsite backup MX that wouldn't have as stringent a filter, or none at all. What you would end up with is three classes of MX records: 1. One High priority record which point to an address tha doesn't answer on SMTP. 2. Medium priority records that point to real mail servers that acccept your mail. 3. One or more low priority records that point to addresses that do not answer on SMTP. What does the collective wisdom of the list think about Nolisting, and the idea of a low preference MX record as well? --- The Vista Content Protection specification could very well constitute the longest suicide note in history -- Peter Gutmann http://www.cs.auckland.ac.nz/~pgut001/pubs/vista_cost.html William Brown Web Development & Messaging Services Technology Services, WNYRIC, Erie 1 BOCES (716)821-7285 _______________________________________________ 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
