Robert A. Rosenberg wrote:
Failure to accept submitted email from Mail Clients on a port
other than Port25 raises a Catch-22 Situation when trying to
connect remotely from a Port25-Blocking (or Hijacking
[...]
Connectivity Provider.
Yes, that's addressed in draft-hutzler-spamops-04.txt and IIRC
also in 2476bis. The SPF I-D has 2476bis in its references.
Adding draft-hutzler-spamops-04 to the references is an option,
but I prefer the existing explanation in 10.4 of the SPF I-D.
Personally I consider block-port-25 schemes as a folly and a
feeble attempt to cure the symptoms of gross negligence on the
side of say "spamcast". It's unrelated to SMTP and SPF, it's
of course possible to send SPF-protected mails from a dyn. IP.
Bye, Frank