Gmail gets my ipv6 instead of ipv4 ! and blocks the email

bikker

My server and dns is properly setup for ipv4 , i dont know why its sending ipv6 to google
as its not setup for ipv6

host gmail-smtp-in.l.google.com[2a00:1450:4010:c01::1a]
said: 550-5.7.25 [2a01:4f9:3b:3a15::2] The IP address sending this message
does not 550-5.7.25 have a PTR record setup, or the corresponding forward
DNS entry does 550-5.7.25 not match the sending IP. As a policy, Gmail does
not accept 550-5.7.25 messages from IPs with missing PTR records. For more
information, go 550-5.7.25 to 550-5.7.25
https://support.google.com/a?p=sender-guidelines-ip 550-5.7.25 To learn
more about Gmail requirements for bulk senders, visit 550 5.7.25
https://support.google.com/a?p=sender-guidelines.
38308e7fff4ca-30b96bf0771si17164071fa.193 - gsmtp (in reply to end of DATA
command)

mendozal

bikker You might want to setup postfix to prefer ipv4

Take a look here
https://clientarea.ramnode.com/knowledgebase/108/Sending-Email-over-IPv4-with-Postfix.html

There's also this approach from mailcow (which should still apply here),
https://community.mailcow.email/d/3760-send-mail-only-using-ipv4

Restart postfix afterwards.

I don't know which one will work, but you can test it and revert back if they don't.

Beni

I had the same problem. Why you do not set up AAAA-Record and PTR for IPv6?. Then it will work.

Kosta

If it was setup properly you wouldn’t had issues. Try again, maybe reading the content from google link will help you?

xyzulu

mendozal You might want to setup postfix to prefer ipv4

@bikker just step PTR records for your IPv6 address. At the least you will learn a little IPv6 which we are all going to need to at some point. IPv6 is nothing to be scared of.