In addition to my previous article about GitLab service desk feature with iRedMail I would like to enhance it a little bit my fixing some missing parts. Starting with connecting to PostgreSQL vmail database:

sudo -u postgres -i
\c vmail

Verifying mail server connectivity and TLS issues.

/opt/gitlab/embedded/bin/openssl s_client -connect mail.domain.com:993

GitLab (and iRedMail also) does not allow expired certificates. So be sure to have both root CA present and your certificate valid.

wget https://letsencrypt.org/certs/2024/r11.pem
cp r11.crt /usr/local/share/ca-certificates/
update-ca-certificates

And finally restarting services. Interesting part is that only Nginx do not allow placing R11 root CA before actual certificate. But placing R11 after actual certificate does the job.

service postfix restart
service dovecot restart
service nginx restart