I keep getting undeliverable messages on emails sent to addresses that use Google. The message tells me this:
mx.google.com #550-5.7.1 [My IPv6 address is here so I removed it] Our system has detected that this 550-5.7.1 message does not meet IPv6 sending guidelines regarding PTR records 550-5.7.1 and authentication. Please review 550-5.7.1 https://support.google.com/mail/?p=ipv6_authentication_error
for more 550 5.7.1 information. v83si4687475qhv.85 - gsmtp ##
I have tried multiple things to fix this issue. We use Comcast, and they tell me they do not have the ability to turn off IPv6 on the modem, and that I need to turn it off on my local machines. That has been done already, with the exception of my server because I am running Exchange and that requires IPv6. Comcast tells me that they cannot set up RDNS on the IPv6 address because they do not have a static IP for IPv6.
Has anyone else who is experiencing this issue found a fix for it?