So I assume that DAVDroid SHOULD try to login with my “name”.
Indeed, see also issue #387.
Is it possible to add this fallback?
I don’t know. I didn’t find the time yet to investigate, and it would certainly change the resource detection logic. High-quality pull requests are always welcome 🙂
Of course login with email would be cool for OwnCloud too, but I didn’t find the time yet to implement checking email address AND local-only part now and I consider it not that high-priority.