To make my mail delivery/reception more stable I recently put a lot of effort in figuring out how to properly setup ptr/spf/dkim/dmarc.
For all domains on my server the domain check on
https://mxtoolbox.com/NetworkTools.aspx are now 100% correct.
I figured that now I could also receive from or send mail to online mail services like Gmail, Outlook.com and whatever online mail service people use nowadays, correctly.
I know that a properly setup ptr/spf/dkim/dmarc is still no guarantee that mail will always arrive but I wasn’t prepared for this.
I got a dmarc report that stated that mailing from some IPv6 IP-address from Gmail to one of my sub-domains was not successful because all spf/dkim/dmarc checks failed.
Of cause, because I have not setup any IPv6 AAAA/ptr/spf/dkim/dmarc for my domain because I do not have an IPv6 address and my SME Server does not support IPv6.
The mail was send from an android phone with Gmail.
How can I prevent Gmail or any other online email provider from trying to send IPv6 mail to my NON-IPv6 enabled domain that hasn’t even got an AAAA-record?
I will have an IPv6 enabled Internet Provider probably within 6 months from now but SME Server still has no support for IPv6 out of the box.
But I could probably help with testing when I have my new IPv6 enabled internet provider...