At 05:53 PM 3/30/2004, James H. Cloos Jr. wrote:
(I don't want to use ptr because I've seen endless spam -- mostly coming
from Korean ipv4s -- where the ptr was falsely set to match the domain the
mail claimed to be from....)
In theory, an SPF client should verify this with a forward lookup. If you
have ptr in the SPF record for example.com, and someone tries to send mail
to you from an IP address that claims to be host.example.com, the client
should then look up host.example.com to see if it matches.
Kelson Vibber
SpeedGate Communications <www.speed.net>