Stuart D. Gathman schreef: > I have a function that recognizes PTR records for dynamic IPs. There > is no hard and fast rule for this - every ISP does it differently, and > may change their policy at any time, and use different conventions in > different places. Nevertheless, it is useful to apply stricter > authentication standards to incoming email when the PTR for the IP > indicates a dynamic IP (namely, the PTR record is ignored since it > doesn't mean anything except to the ISP). This is because Windoze > Zombies are the favorite platform of spammers.
Did you also think about ISPs that use such a PTR record for both dynamic and fixed IPs? -- JanC "Be strict when sending and tolerant when receiving." RFC 1958 - Architectural Principles of the Internet - section 3.9 -- http://mail.python.org/mailman/listinfo/python-list
