@nebulon Thank you for taking a look!
My problem has just been solved!
It started for me because your DOCS did not make it clear that Creating a Mailbox was a whole separate Necessity even for the ADMIN. And that as an ADMIN who Added a User with the whole Email Invitation sent, user responding, creating their own Username, and Saving this DID NOT by DEFAULT at least finish the process by Adding a new mailbox corresponding to the new User .
I never guessed that THE ADMIN him or herself of the Cloudron installation would not have access AS THE ADMIN to setup Master default parameters for the Email App itself!
In your docs after following along with the entire Email setup down to the check the Status instructions at last continuing down the page it merely says, casually, as if an Option --
Mailboxes can be created for Users and Groups on a per-domain level. To do so, simply create them in the Email view.*
Mailboxes can be created for Users
when it should really be highlighted as
Now mailboxes must be set up here for your users if you intend to offer this as a feature.
Nothing indicating that we are continuing in the Enabling Emails for Users instructions or after all of the above it still won't work.
That not even the ADMIN now enacting all these steps Must manually install an Email box for him/herself.
How about "Finally, you must Finish this process by adding each User's Mailbox manually. These were not created automatically when you finished creating the User. In fact, You must first make an Email Box for yourself with Superadmin privileges or you will not be able to Login to the Email application to customize it according to your preferences.
It was finally only by reading carefully https://forum.cloudron.io/topic/4529/cloudron-email-wrong-usernam that I realized any advice I received about my email problem was ASSUMING that I knew this -- even though everytime I read your Docs I was assuming that the Mailboxes were automatically installed, certainly for the Admin first of all.
I'd recommend really emphasizing this in your docs as a clear Step 1 through Step 10(?) process REQUIRED Final step or not even the Cloudron Admin can enter his own Email installation.