PSA: We're aware of an issue affecting #Thunderbird users using #IMAP to connect to certain #Microsoft account servers (for example: outlook.office365.com).
These users are receiving an error message that says "User is authenticated but not connected."
We believe this is caused by Microsoft running certain services with broken #IPv6 functionality.
WORKAROUND: Disable IPv6 networking in Thunderbird's advanced config.
@thunderbird I deleted Microsoft completely instead. Also works great
@MartinH This is a 100% legitimate solution