I have the SMTP settings defined in gitlab.rb but it looks like they’re not taking effect and gitlab is defaulting to using postfix on localhost instead.
Likewise I can manually add the /var/opt/gitlab/gitlab-rails/smtp_settings.rb and link it to /opt/gitlab/embedded/service/gitlab-rails/config/initializers/smtp_settings.rb and restart gitlab which will use those settings and appear to work but it will get deleted on the next re-configuration.
gitlab-ctl reconfigure | grep smtp
- templatesymlink[Create a smtp_settings.rb and create a symlink to Rails root] action delete
- file[/var/opt/gitlab/gitlab-rails/etc/smtp_settings.rb] action delete (up to date)
- link[/opt/gitlab/embedded/service/gitlab-rails/config/initializers/smtp_settings.rb] action delete (up to date)
Running 11.6.3 (Just upgraded from 11.6.1 to see if that fixed the problem) on Ubuntu 16.04