Andriy G. Tereshchenko wrote:
Not all IPs assigned to Juno has untd.com PTR data.
All IP addresses that sent legitimate mail to my domain saying "MAIL
FROM:<(_dot_)(_dot_)(_dot_)(_at_)juno(_dot_)com>" had untd.com PTR data.
PTR does not solve routing problem created with SPF.
The 'ptr' mechanism is not for solving the routing problem. It is just an
abbreviation for a large list of IP addresses.
Note: The use of source routing is discouraged. Unless the
sender has special need of path restriction, the choice
of transmission route should be left to the mail transport service.
If you used the source routing, you would not have to add the SUBMITTER
parameter to the MAIL comand. And it would work even with the old SMTP (not
ESMTP).
Roger