Allow mailbox creation via resource server

[qbey]

Feature Request

Allow email account through API.

Describe the solution you'd like

An authenticated user should be allowed to create a new mailbox though a resource server (OIDC authenticated with token introspection) URL.

Describe alternatives you've considered

The resource server mode is the most secure, has it can check the user has permission to create a mailbox. Using API key credential is not considered yet as it would provide too much access.
We could look to add a key credential restricted to specific domains?

Discovery, Documentation, Adoption, Migration Strategy

If you can, explain how users will be able to use this and possibly write out a version the docs (if applicable).
Maybe a screenshot or design?

Do you want to work on it through a Pull Request?

• new resource server URLs -> yes
• API key credential -> not planned