Hi all,
I've a generic question to all more experienced than me postfix users here: Is it nowadays (reasonable) possible to run postfix with IPv6 only? E.g "mail.example.com" and "smtp.example.com" with only ipv6 AAAA records in the DNS, no A / ipv4 anymore? Michael ----- EOM for impatient readers :-) ------- Hi patient readers :-) reason for my question: I'm running my own small postfix/dovecot etc. environment on a VPS. Running fine for years now, after some initial work to get my sent emails not delivered as junk. spf record exists for my few domains, dkim is active and passes everytime, dmarc entry is active. https://www.mail-tester.com gives me 10/10 :-) All relevant for me email providers are accepting my emails without any issue, for long, except Microsoft hotmail/outlook. Registered for SNDS, and JMRP feed is activated. IPv4 adress is "clean" and fine for outlook.com. BUT nevertheless all emails from me to any outlook.* or hotmail.* recipients is delivered to their junk folder. I strongly believe that this is because of the (hopefully) only "issue" left I know about: My PTR. As I have a small VPS with only one IPV4 included in price, I've set the PTR to "example.com" and not to "mail.example.com", which is the fqdn for my outgoing postfix sent mail. Of course I know that this is a "should not", but as there's a lot of stuff running e.g. on Apache on this machine, a nextcloud instance, a TYPO3 instance, roundcubemail, jitsi meet, ..., all on separate subdomains like "cloud.example.com", "webmail.example.com", "meet.example.com" etc., I simply don't like to have an "unclean" PTR, pointing not the main/base domain. "Only" because of antispam. As said I have only one IPv4 for my VPS, but a /64 IPv6 subnet. So more than enough IPv6 addreses to give each of my few domains amd not that many subdomains a unique IPv6, with a corresponding PTR. I'm only not sure if there might be "IPv4-only" email providers out there, whose emails might not be routed to my "IPv6-only" postfix. Sorry for this long email :-) Regards, Michael
