Exchange 2016 getting bounce backs from google:
mx.google.com gave this error:
[2601:40d:8001:dc00:5436:c
102:4af2:5
c68] Our system has detected that this message does not meet IPv6 sending guidelines regarding PTR records and authentication. Please review
https://support.google.com/mail/?p=IPv6AuthError for more information . f10si1906405ioi.62 - gsmtp
I cannot figure this out for the life of me. If it's as simple as a radio box I might just cry. lol