On an Ubuntu 18.04 Server (VM), I have a gitlab omnibus installation (12.10.6) configured with an LDAP login. Besides LDAP, I didn't change the configuration defaults.
At the moment, gitlab hasn't been able to send e-mails for example for mentions in Issues etc. Here's an excerpt of /var/log/mail.log (I've changed the real domains and usernames but other than that it's the actual log):
Jul 27 16:33:53 gitlab postfix/pickup[16154]: 8FA4014029F: uid=998 from=<gitlab@mydomain.intern>
Jul 27 16:33:53 gitlab postfix/cleanup[16388]: 8FA4014029F: message-id=<5f1f01f181310_47783fde5a8fe594660e1@gitlab.mail>
Jul 27 16:33:53 gitlab postfix/qmgr[16155]: 8FA4014029F: from=<gitlab@mydomain.intern>, size=27348, nrcpt=1 (queue active)
Jul 27 16:33:59 gitlab postfix/smtp[16394]: 8FA4014029F: to=<user1@externaldomain.de>, relay=postrelay1.lrz.de[129.187.255.160]:25, delay=5.7, delays=0.07/0.01/5.5/0.11, dsn=5.0.0, status=bounced (host postrelay1.lrz.de[129.187.255.160] said: 550 Requested action not taken: mailbox unavailable (in reply to RCPT TO command))
Jul 27 16:33:59 gitlab postfix/cleanup[16388]: 3B7B81425B6: message-id=<20200727163359.3B7B81425B6@mydomain.intern>
Jul 27 16:33:59 gitlab postfix/bounce[16401]: 8FA4014029F: sender non-delivery notification: 3B7B81425B6
Jul 27 16:33:59 gitlab postfix/qmgr[16155]: 3B7B81425B6: from=<>, size=29499, nrcpt=1 (queue active)
Jul 27 16:33:59 gitlab postfix/qmgr[16155]: 8FA4014029F: removed
Jul 27 16:33:59 gitlab postfix/local[16402]: 3B7B81425B6: to=<gitlab@mydomain.intern>, relay=local, delay=0.04, delays=0.01/0.01/0/0.02, dsn=2.0.0, status=sent (delivered to mailbox)
Jul 27 16:33:59 gitlab postfix/qmgr[16155]: 3B7B81425B6: removed
Jul 27 16:45:03 gitlab postfix/pickup[16154]: DCECD14029F: uid=998 from=<gitlab@mydomain.intern>
Jul 27 16:45:03 gitlab postfix/cleanup[17791]: DCECD14029F: message-id=<note_77@mydomain.intern>
Jul 27 16:45:03 gitlab postfix/qmgr[16155]: DCECD14029F: from=<gitlab@mydomain.intern>, size=4954, nrcpt=1 (queue active)
Jul 27 16:45:04 gitlab postfix/smtp[17794]: DCECD14029F: to=<user2@otherdomain.biz>, relay=smtpin.rzone.de[81.169.145.97]:25, delay=0.3, delays=0.05/0.02/0.15/0.08, dsn=5.0.0, status=bounced (host smtpin.rzone.de[81.169.145.97] said: 550 Requested action not taken: mailbox unavailable (in reply to RCPT TO command))
Jul 27 16:45:04 gitlab postfix/cleanup[17791]: 31EDC1425B6: message-id=<20200727164504.31EDC1425B6@mydomain.intern>
Jul 27 16:45:04 gitlab postfix/bounce[17795]: DCECD14029F: sender non-delivery notification: 31EDC1425B6
Jul 27 16:45:04 gitlab postfix/qmgr[16155]: 31EDC1425B6: from=<>, size=7094, nrcpt=1 (queue active)
Jul 27 16:45:04 gitlab postfix/qmgr[16155]: DCECD14029F: removed
Jul 27 16:45:04 gitlab postfix/local[17797]: 31EDC1425B6: to=<gitlab@mydomain.intern>, relay=local, delay=0.05, delays=0.03/0.01/0/0.01, dsn=2.0.0, status=sent (delivered to mailbox)
Jul 27 16:45:04 gitlab postfix/qmgr[16155]: 31EDC1425B6: removed
When attempting to email user1@externaldomain.de it contacts postrelay1.lrz.de but the mail is bounced with 550 Requested action not taken: mailbox unavailable (in reply to RCPT TO command). I have checked several times that the username is correct and mail can be delivered to that recipient outside the gitlab server. Besides, the same thing happens with other domains for example user2@otherdomain.biz in smtpin.rzone.de so I think the problem lies elsewhere.
I've read sometimes 550 could also mean the server is considering the email as spam... But I am not very familiar with mail servers.
Here's the postfix main.cf:
alias_database = hash:/etc/aliases
alias_maps = hash:/etc/aliases
append_dot_mydomain = no
biff = no
compatibility_level = 2
inet_interfaces = all
inet_protocols = ipv4
mailbox_size_limit = 0
mydestination = $myhostname, mydomain.intern, gitlab, localhost.localdomain, localhost
myhostname = mydomain.intern
mynetworks = 127.0.0.0/8 [::ffff:127.0.0.0]/104 [::1]/128
myorigin = /etc/mailname
readme_directory = no
recipient_delimiter = +
relayhost =
smtp_tls_session_cache_database = btree:${data_directory}/smtp_scache
smtpd_banner = $myhostname ESMTP $mail_name (Ubuntu)
smtpd_relay_restrictions = permit_mynetworks permit_sasl_authenticated defer_unauth_destination
smtpd_tls_cert_file = /etc/ssl/certs/ssl-cert-snakeoil.pem
smtpd_tls_key_file = /etc/ssl/private/ssl-cert-snakeoil.key
smtpd_tls_session_cache_database = btree:${data_directory}/smtpd_scache
smtpd_use_tls = yes
Any pointers or ideas appreciated
