A college of my has struggled days with this issue, gmail wouldn't accept any mail send from a IPv6, ended up disabling IPv6 at the end. It seems like google only uses IPv6 for internal mail's, sending a mail to another account sends them using IPv4. Even Facebook, Microsoft etc still use IPv4 for their email's.
Re:Google moves to replace Flash with HTML5
by dingaling on Friday May 20, 2016 @10:03AM
(#11737824)
Google do of course use IPv6 externally, but require rDNS for all inbound IPv6 SMTP sessions. Without that set for your MTA's host they'll reject immediately.
thanks for the thought, I'll check but pretty sure I', stil on IPv4, 6 not enabled, maybe I'll try enabling it, or burning some sort of effigy, http://www.mail-tester.com/ is the link I intended.
Okay, jumped some hoops for m$ to try and get my email working, but no joy, sender.office.com reports the IP is not blocked and suggests I refer to bounce error (there is no bounced message), I tried the Outlook mitigation route, and after 24 hours received a "Not qualified for mitigation
... Our investigation has determined that the above IP(s) do not qualify for mitigation." message (my stars). Today I've joined the Microsoft Smart Network Data service, and that reports the IP of the mailserver as having normal service, so where now ? PM Bill?
On the other hand, I don't know anyone with an @some-microsoft-property email address, so I don't know whether I'll be having trouble sending things there. I can reach Gmail and Yahoo (and after getting my own /64, Comcast) without trouble, though.
EDIT: Hmmm, mail-test.com seems to be a parked domain.