Mailsending ipv6 to Google-Mailservice fails

Hi!

If I our mailserver sends mails to gmail, the delivering fails. This is the bounce of gMail

Code:

                   The mail system

<[email protected]>: host
    gmail-smtp-in.l.google.com[2a00:1450:4025:402::1a] said: 550-5.7.1
    [2a01:4f8:212:f65::2] Our system has detected that this message does
    550-5.7.1 not meet IPv6 sending guidelines regarding PTR records and
    550-5.7.1 authentication. Please review 550-5.7.1
    https://support.google.com/mail/?p=IPv6AuthError for more information 550
    5.7.1 . w13-20020a05640234cd00b0043bd6cf51d1si5536605edc.530 - gsmtp (in
    reply to end of DATA command)

Reporting-MTA: dns; tesoro2.products4more.at
X-Postfix-Queue-ID: D8ECA4A21450
X-Postfix-Sender: rfc822; [email protected]
Arrival-Date: Sun, 14 Aug 2022 02:16:05 +0200 (CEST)

Final-Recipient: rfc822; [email protected]
Original-Recipient: rfc822;[email protected]
Action: failed
Status: 5.7.1
Remote-MTA: dns; gmail-smtp-in.l.google.com
Diagnostic-Code: smtp; 550-5.7.1 [2a01:4f8:212:f65::2] Our system has detected
   that this message does 550-5.7.1 not meet IPv6 sending guidelines regarding
   PTR records and 550-5.7.1 authentication. Please review 550-5.7.1
   https://support.google.com/mail/?p=IPv6AuthError for more information 550
   5.7.1 . w13-20020a05640234cd00b0043bd6cf51d1si5536605edc.530 - gsmtp

If I check the PTR-Record of our system (https://network-tools.webwiz.net/reverse-dns.htm)
all seems fine. There is a PTR-Record to 2a01:4f8:212:f65:: which we set on the admin-panel of our server-provider. Take a look on this screenshot.
https://ibb.co/myKGZrg [/IMG]

Now lets have a look to

Code:

[email protected] # ifconfig
enp0s31f6: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 1500
        inet 136.243.47.106  netmask 255.255.255.192  broadcast 136.243.47.127
        inet6 fe80::921b:eff:fedb:519  prefixlen 64  scopeid 0x20<link>
        inet6 2a01:4f8:212:f65::2  prefixlen 64  scopeid 0x0<global>

Any ideas what is to do, to make the delivering to gmail possible?

Thanks in advance, Martin

 

Thank you - I read this before your post, but I thought in the meanwhile there are some new insights for this google-phenomen.

I did as you described, works well! Thanks again!

 

Hm - the posted solution works for mail pointing directly to gmail but not for domains which are hosted at googleservices.

So, if we send mails to [email protected] there comes the following bounce

Code:

Betreff:     Undelivered Mail Returned to Sender
Datum:     Fri, XX XXXX 2022 14:32:08 +0200 (CEST)
Von:     Mail Delivery System <[email protected]>
An:     [email protected]


This is the mail system at host tesoro2.products4more.at.

I'm sorry to have to inform you that your message could not
be delivered to one or more recipients. It's attached below.

For further assistance, please send mail to postmaster.

If you do so, please include this problem report. You can
delete your own text from the attached returned message.

The mail system

<[email protected]>: host ASPMX.L.GOOGLE.COM[2a00:1450:4025:402::1a]
said: 550-5.7.1 [2a01:4f8:212:f65::2] Our system has detected that this
message does 550-5.7.1 not meet IPv6 sending guidelines regarding PTR
records and 550-5.7.1 authentication. Please review 550-5.7.1
https://support.google.com/mail/?p=IPv6AuthError for more information 550
5.7.1 . cr13-20020a170906d54d00b00730632d2a0fsi1725389ejc.452 - gsmtp (in
reply to end of DATA command)

We got 4 such bounces in the last days for different domains, so fixing that with transportmaps is rather cumbersome.

Any other ideas how to fix that ip4/ip6-problem?

TIA, Martin

 

Yes till, you are right - but I did a IPv6-setup as mentioned in my initial post.

Here is another small piece of the puzzle to confirm the correctness of the setup

Code:

#ip -6 addr show scope global
2: enp0s31f6: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 state UP qlen 1000
    inet6 2a01:4f8:212:f65::2/64 scope global
       valid_lft forever preferred_lft forever

and the proof of ptr-check-service

https://ibb.co/BnCMQrg

 

thank you - additional ptr is done. so lets have a look if that helped.