David Woodhouse <dwmw2(_at_)infradead(_dot_)org> writes:
But SPF doesn't work without SRS.
David: It is statements like that where you lose all credibility.
SPF does work, without SRS.
Without all forwarders using SRS, there is a chance that you will get
a false positive due to the forwarding, but false positives happen all
the time with modern day email. Saying that "SPF doesn't work" is
like saying "spam filtering doesn't work".
Even without SRS, SPF can still work just fine if the people who set
up the forwarding whitelist their forwarders, or of domain owners who
publish SPF records use ABBS/SES/BATV and the stub-DNS server trick.
As Scott Kitterman pointed out with his review of the SPF support
requests, and as I can confirm with the T-FWL listing requests (or
lack there of), and as many of us who publish records with -all can
tell by the lack of rejections, forwarding just isn't a huge problem