Relay not allowed error returned when trying to send emails to gmail and yahoo

[ghevge]

I can receive emails on my mail server instance, but when trying to send an email from thunderbird I get the error:

An error occurred while sending mail. The mail server responded:
Relay not allowed..
Please check the message recipient “[email protected]” and try again.

In the email server logs I don't see any errors or warnings. The only entries that seem to be related to this delivery try are:

�[2m2023-08-14T19:05:59.604649Z�[0m �[32m INFO�[0m �[1msession�[0m�[1m{�[0m�[3minstance�[0m�[2m=�[0m"smtp" �[3mprotocol�[0m�[2m=�[0mSmtp �[3mremote.ip�[0m�[2m=�[0m"::ffff:209.85.208.42" �[3mremote.port�[0m�[2m=�[0m59609�[1m}�[0m�[2m:�[0m �[2mutils::listener::listen�[0m�[2m:�[0m �[3mcontext�[0m�[2m=�[0m"tls" �[3mevent�[0m�[2m=�[0m"handshake" �[3mversion�[0m�[2m=�[0mTLSv1_3 �[3mcipher�[0m�[2m=�[0mTLS13_AES_256_GCM_SHA384
�[2m2023-08-14T19:06:29.928743Z�[0m �[32m INFO�[0m �[1msession�[0m�[1m{�[0m�[3minstance�[0m�[2m=�[0m"smtp" �[3mprotocol�[0m�[2m=�[0mSmtp �[3mremote.ip�[0m�[2m=�[0m"::ffff:209.85.208.42" �[3mremote.port�[0m�[2m=�[0m59609�[1m}�[0m�[2m:�[0m �[2msmtp::queue::spool�[0m�[2m:�[0m Message queued for delivery. �[3mcontext�[0m�[2m=�[0m"queue" �[3mevent�[0m�[2m=�[0m"scheduled" �[3mid�[0m�[2m=�[0m5040322485 �[3mfrom�[0m�[2m=�[0m"[email protected]" �[3mnrcpts�[0m�[2m=�[0m1 �[3msize�[0m�[2m=�[0m4959
�[2m2023-08-14T19:06:29.936153Z�[0m �[32m INFO�[0m �[1mdelivery�[0m�[1m{�[0m�[3mid�[0m�[2m=�[0m5040322485 �[3mreturn_path�[0m�[2m=�[0m"[email protected]" �[3mnrcpt�[0m�[2m=�[0m1 �[3msize�[0m�[2m=�[0m4959�[1m}�[0m�[2m:

In trace mode I get some more logs but nothing relevant. Basically the same error: relay not allowed

�[2m2023-08-14T20:08:04.936294Z�[0m �[34mDEBUG�[0m �[1msession�[0m�[1m{�[0m�[3minstance�[0m�[2m=�[0m"smtp" �[3mprotocol�[0m�[2m=�[0mSmtp �[3mremote.ip�[0m�[2m=�[0m"::ffff:138.229.16.231" �[3mremote.port�[0m�[2m=�[0m47650�[1m}�[0m�[2m:�[0m �[2msmtp::inbound::mail�[0m�[2m:�[0m �[3mcontext�[0m�[2m=�[0m"mail-from" �[3mevent�[0m�[2m=�[0m"success" �[3maddress�[0m�[2m=�[0m"[email protected]"
�[2m2023-08-14T20:08:04.936401Z�[0m �[35mTRACE�[0m �[1msession�[0m�[1m{�[0m�[3minstance�[0m�[2m=�[0m"smtp" �[3mprotocol�[0m�[2m=�[0mSmtp �[3mremote.ip�[0m�[2m=�[0m"::ffff:138.229.16.231" �[3mremote.port�[0m�[2m=�[0m47650�[1m}�[0m�[2m:�[0m �[2msmtp::inbound::session�[0m�[2m:�[0m �[3mevent�[0m�[2m=�[0m"write" �[3mdata�[0m�[2m=�[0m"250 2.1.0 OK\r\n" �[3msize�[0m�[2m=�[0m14
�[2m2023-08-14T20:08:04.936491Z�[0m �[35mTRACE�[0m �[2mdirectory::sql::lookup�[0m�[2m:�[0m �[3mcontext�[0m�[2m=�[0m"directory" �[3mevent�[0m�[2m=�[0m"query" �[3mquery�[0m�[2m=�[0m"SELECT 1 FROM emailserver.emails WHERE address LIKE '%@' || $1 LIMIT 1" �[3mparams�[0m�[2m=�[0m["mydomain.com"]
�[2m2023-08-14T20:08:04.945551Z�[0m �[35mTRACE�[0m �[1msession�[0m�[1m{�[0m�[3minstance�[0m�[2m=�[0m"smtp" �[3mprotocol�[0m�[2m=�[0mSmtp �[3mremote.ip�[0m�[2m=�[0m"::ffff:138.229.16.231" �[3mremote.port�[0m�[2m=�[0m47650�[1m}�[0m�[2m:�[0m �[2msmtp::inbound::session�[0m�[2m:�[0m �[3mevent�[0m�[2m=�[0m"read" �[3mdata�[0m�[2m=�[0m"RCPT TO:<[email protected]>\r\n" �[3msize�[0m�[2m=�[0m35
�[2m2023-08-14T20:08:04.959706Z�[0m �[34mDEBUG�[0m �[1msession�[0m�[1m{�[0m�[3minstance�[0m�[2m=�[0m"smtp" �[3mprotocol�[0m�[2m=�[0mSmtp �[3mremote.ip�[0m�[2m=�[0m"::ffff:138.229.16.231" �[3mremote.port�[0m�[2m=�[0m47650�[1m}�[0m�[2m:�[0m �[2msmtp::inbound::rcpt�[0m�[2m:�[0m Relay not allowed. �[3mcontext�[0m�[2m=�[0m"rcpt" �[3mevent�[0m�[2m=�[0m"error" �[3maddress�[0m�[2m=�[0m"[email protected]"
�[2m2023-08-14T20:08:05.005415Z�[0m �[32m INFO�[0m �[1mdelivery�[0m�[1m{�[0m�[3mid�[0m�[2m=�[0m745358884 �[3mreturn_path�[0m�[2m=�[0m"[email protected]" �[3mnrcpt�[0m�[2m=�[0m1 �[3msize�[0m�[2m=�[0m1865�[1m}�[0m�[2m:�[0m�[1mattempt�[0m�[1m{�[0m�[3mdomain�[0m�[2m=�[0m"mydomain.com" �[3mattempt_number�[0m�[2m=�[0m0�[1m}�[0m�[2m:�[0m �[2msmtp::outbound::local�[0m�[2m:�[0m �[3mcontext�[0m�[2m=�[0m"deliver_local" �[3mevent�[0m�[2m=�[0m"delivered" �[3mrcpt�[0m�[2m=�[0m"[email protected]"
�[2m2023-08-14T20:08:05.005559Z�[0m �[32m INFO�[0m �[1mdelivery�[0m�[1m{�[0m�[3mid�[0m�[2m=�[0m745358884 �[3mreturn_path�[0m�[2m=�[0m"[email protected]" �[3mnrcpt�[0m�[2m=�[0m1 �[3msize�[0m�[2m=�[0m1865�[1m}�[0m�[2m:�[0m �[2msmtp::outbound::delivery�[0m�[2m:�[0m Delivery completed. �[3mcontext�[0m�[2m=�[0m"queue" �[3mevent�[0m�[2m=�[0m"completed"
�[2m2023-08-14T20:08:09.962051Z�[0m �[35mTRACE�[0m �[1msession�[0m�[1m{�[0m�[3minstance�[0m�[2m=�[0m"smtp" �[3mprotocol�[0m�[2m=�[0mSmtp �[3mremote.ip�[0m�[2m=�[0m"::ffff:138.229.16.231" �[3mremote.port�[0m�[2m=�[0m47650�[1m}�[0m�[2m:�[0m �[2msmtp::inbound::session�[0m�[2m:�[0m �[3mevent�[0m�[2m=�[0m"write" �[3mdata�[0m�[2m=�[0m"550 5.1.2 Relay not allowed.\r\n" �[3msize�[0m�[2m=�[0m30
�[2m2023-08-14T20:08:09.976640Z�[0m �[35mTRACE�[0m �[1msession�[0m�[1m{�[0m�[3minstance�[0m�[2m=�[0m"smtp" �[3mprotocol�[0m�[2m=�[0mSmtp �[3mremote.ip�[0m�[2m=�[0m"::ffff:138.229.16.231" �[3mremote.port�[0m�[2m=�[0m47650�[1m}�[0m�[2m:�[0m �[2msmtp::inbound::session�[0m�[2m:�[0m �[3mevent�[0m�[2m=�[0m"read" �[3mdata�[0m�[2m=�[0m"" �[3msize�[0m�[2m=�[0m0
�[2m2023-08-14T20:08:09.976679Z�[0m �[34mDEBUG�[0m �[1msession�[0m�[1m{�[0m�[3minstance�[0m�[2m=�[0m"smtp" �[3mprotocol�[0m�[2m=�[0mSmtp �[3mremote.ip�[0m�[2m=�[0m"::ffff:138.229.16.231" �[3mremote.port�[0m�[2m=�[0m47650�[1m}�[0m�[2m:�[0m �[2msmtp::inbound::spawn�[0m�[2m:�[0m Connection closed by peer. �[3mevent�[0m�[2m=�[0m"disconnect" �[3mreason�[0m�[2m=�[0m"peer"

Any idea what could be wrong?

Thanks

[ghevge]

It sounds like the problem is caused by the fact that I'm trying to install my mail server behind a dynamic IP, with no rDNS entries defined.
https://serverfault.com/questions/1141609/550-5-1-2-relay-not-allowed-error-returned-when-trying-to-send-emails-from-my?noredirect=1#comment1488976_1141609

[mdecimus]

You need to authenticate in order to be able to relay. Have you entered a valid username and password in thunderbird?

[ghevge]

Yes. I'm able to send emails to my domain accounts. It only fails when trying to send them to outside email accounts.

[ghevge]

I am waiting now for my ISP to see if they can provide me a static IP so that I can test this.