Problem: Job exception: 500 5.5.2 unrecognized command
Following default discourse install using the official guide, email was not sent out for admin account creation after successful installation.
Checking the log
/var/discourse# tail shared/standalone/log/rails/production.log
Found the following error:
Sent mail to firstname.lastname@example.org (1499.0ms)
[default] Job exception: 500 5.5.2 unrecognized command
This was the more detailed error shown in sidekiq after successfully resolved the problem using solution below:
Jobs::HandledExceptionWrapper: Wrapped Net::SMTPAuthenticationError: 500 5.5.2 unrecognized command
Solution: uncomment the SMTP port in app.yml
Found the solution from Discourse Meta: uncomment the port setting in app.yml to explicitly use port 587. Rebuild app and it should work now.
Suspected the reason being default port was not applied during manual bootstrap due to not following the default prompt and instead manually bootstrapped app after editing app.xml to change the default from email used to comply with SparkPost.