how to fix ( Mail delivery failed: returning message to sender)

hi
how to fix this error in roundcube:

This message was created automatically by mail delivery software.

A message that you sent could not be delivered to one or more of its
recipients. This is a permanent error. The following address(es) failed:

[email protected]
host gmail-smtp-in.l.google.com [2a00:1450:400c:c00::1a]
SMTP error from remote mail server after pipelined end of data:
550-5.7.1 [2a01:4f8:1c0c:5aef::1] 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 . h28si2237251wrc.145 - gsmtp
Reporting-MTA: dns; server.domain.com

Action: failed
Final-Recipient: rfc822;[email protected]
Status: 5.0.0
Remote-MTA: dns; gmail-smtp-in.l.google.com
Diagnostic-Code: smtp; 550-5.7.1 [2a01:4f8:1c0c:5aef::1] 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 . h28si2237251wrc.145 - gsmtp

Hello,


You can not fix this error in roundcube.


If you are a server owner you should read what Gmail writes:






and fix the issue with IPv6 (please search the forums for the similar threads, it already has answers and guides on the matter).


If you are a client of a hosting company you should contact them for a help.

zEitEr said:

Hello,


You can not fix this error in roundcube.


If you are a server owner you should read what Gmail writes:

Code:

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

and fix the issue with IPv6 (please search the forums for the similar threads, it already has answers and guides on the matter).

If you are a client of a hosting company you should contact them for a help.

Click to expand...

yes i am owner , but i can't fix it !

And one more thing: dovecot 2.3.0.1 (ffd8a29) is Running but hidden in Service Monitor !!

zEitEr said:

Hello,


You can not fix this error in roundcube.


If you are a server owner you should read what Gmail writes:

Code:

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

and fix the issue with IPv6 (please search the forums for the similar threads, it already has answers and guides on the matter).


If you are a client of a hosting company you should contact them for a help.

Click to expand...

yup
had to deal with this few years ago but I cannot remember everything I had to do to fix it. but it was PTR record with ipv6 (perhaps dynamic????) I had to correct on server dns zone.

Directadmin is not responsible for setting correct PTR records for used IPs. You should do it via your server management interface, and please read: https://support.google.com/mail/?p=IPv6AuthError