I’m using built-in mail server and ran into issue with voicemail delivery to gmail.
Intermittently it will fail to deliver and the error is:
Our system has detected that 550-5.7.1 this message does not meet IPv6 sending guidelines regarding PTR 550-5.7.1 records and authentication. Please review 550-5.7.1 https://support.google.com/mail/?p=IPv6AuthError for more information 550 5.7.1
BTW, I’m not using IPv6 at all.
Is there a workaround to this issue?
If not, what is everyone using to deliver voicemail?