Addressed comments

Test, cleanup

Fixed in master

I think everything besides the Docker FROM changes can be merged because it doesn't impact anything existing either way.

Cleanup

Removed print statement

To be able to validate things we now just validate first, and then create everything, and bail out if user or domain are preexisting.
There's doesn't seem to really be a point in converting existing users.

Fixed mail options

Adapt to recent changes

Fixed, sorry about the downtime.

https://phorge.apps.ocp04.ait-msp-infra.net/T265

it's not, and I'm also not sure if this really solves anything since we actually try to keep the balance around 10 CHF (I think?). Maybe the better solution would be to just prominently display a warning that the user is being rate limited.

We want to use app.password only when *not* in production of course

I used this to create new users on demoresller.kolab.klab.cc and I don't see why not.

I guess not setting a password would be an alternative if that works... The random password is just there until somebody sets one that somebody knows.

No changes

A note on why would be good in the commit message.