Using this behind an NGINX SSL Proxy for Mattermost, I get an internal server error

[hugbubby]

Relevant log here:

{"level":"error","ts":1592987370.158914,"caller":"mlog/log.go:175","msg":"Connection unsuccessful: SendMail: Failed to authenticate on SMTP server., 451 4.3.2 Internal server error","path":"/api/v4/email/test","request_id":"hbu51jrw4ibezycaa48m7wd9ia","ip_addr":"172.91.91.228","user_id":"pjgmzrp4u3yr9p8q5iwiz5c3mw","method":"POST","err_where":"testEmail","http_code":500,"err_details":""}

So somewhere along the lines the hydroxide server responds with: 451 4.3.2 Internal server error

Which I don't think should happen.

Here's how to reproduce this:

1. Make an EC2 instance
2. Install mattermost
3. Setup an nginx ssl proxy
4. Authenticate and start hydroxide
5. Hit the "test connection" button

I'll try various things to fix this issue for a bit, and then I'll just head over to protonmail-bridge for now. It has a headless mode now too btw, although it still sucks and has tons of dependencies.

[emersion]

Debug logs on the hydroxide side would be useful