Fix automatic provisioning (for new users)

[ChristophWurst]

This makes sure that every user has a provisioned account when Mail is accessed.

Before

new user didn't have provisioned account until admin provisioned for all users

After

also new users get their account as soon as they access the app

In the future we can use nextcloud/server#18348 to create the account right when the user is created. But it doesn't make a difference at the moment.

[republicus]

Yes, please :)
I created a feature request issue at nextcloud/user_external that partially makes this request.
nextcloud/user_external#120 (comment)

Additionally, it would be useful if the user_external app were to also populate the user's email.

Mail app auto provision would be useful on a mail server with multiple domains by provisioning %EMAIL% instead of %USERID%@domain.com

That's already possible with provisioning. But, for other backend authentications, the email is not populated. So provisioning for multiple domains, while making use of %EMAIL%, doesn't work for for all backends.

[ChristophWurst]

Additionally, it would be useful if the user_external app were to also populate the user's email.

Makes sense. Mind opening a feature request?

[republicus]

@ChristophWurst should the feature request you asked for be submitted in Mail?
The link I shared above is a feature request at nextcloud/user_external

I'm happy to reproduce it here if that is the right place for it.

PS. The automatic provisioning is working beautifully now.

[ChristophWurst]

My mail server's logon username credentials is the user's full email -- so the user's email is already known and passed on the first login with user_external.

Possibly the same as #2566?