Describe the bug
I am using Mailgun as a SMTP host for all other apps on my server and it is working fine, including through local Postfix (sendmail). However, no matter what I set my MAILER_DSN to in the configuration for the Docker install (I wasn't able to get the bare metal install working), Mbin refuses to send out e-mails. Perhaps someone with Docker who is familiar with SMTP setup could point out what the issue might be, or how to debug it at least?

On which Mbin instance did you find the bug?
Currently Down

Which Mbin version was running on the instance?
1.9.0

To Reproduce
Steps to reproduce the behavior:
Attempt to use any functionality that uses e-mails (password resets, etc.)

Expected behavior
Some configuration of MAILER_DSN should work, especially a verified one

Desktop (please complete the following information):

• OS: [e.g. macOS]
• Browser: [Firefox]
• Browser Version: [e.g. 147]