Checklist

• I have used the search function to see if someone else has already submitted the same feature request.
• I will describe the problem with as much detail as possible.
• This issue only contains a request for one single feature, not multiple (related) features.

App version

6.711

Problem you are trying to solve

The licenses for Office 365 used by a charity that I volunteer for have been downgraded by Microsoft. This means that the only open protocol that can be used for managing email is POP3. K-9 Mail currently does not allow OAuth 2.0 authentication to be used for POP3 accounts..

Suggested solution

Implement OAuth 2.0 authentication for POP3 accounts.

Screenshots / Drawings / Technical details

No response