[PLUG] Mail Administration Question

[Rich Shepard]

   Much spam passing current postfix UCE filters and landing in the INBOX are
from IP addresses that do not resolve to a domain name. The headers include
a 'Received: from <some_domain_name> (unknown [nnn.ooo.ppp.qqq])'.

   Is the unknown IP address a reliable indicator of spam? A Web search did
not answer this question. One hit, to an Apple mail forum, suggested that it
can be the result of some (many?) Mac admins not correctly configuring their
DNS servers.

   Might adding a rule to reject unknown IP addresses produce unintended
consequences of rejecting legitimate non-maillist messages?

Rich