iOS 13.3.1 - cannot send any email
Phone has been working forever, but no all of a sudden, all outgoing mail is saved to Outbox with the following error "Cannot Send Mail. The server rejected one of the recipient's addresses. The message has been placed in your Outbox."
This is the same for two different accounts (one is Outlook.com - so no config required, and the other is an IMAP account on a server I have control of)
Device is configured correctly (it's always worked), and I have tried the same accounts on a different device successfully (i.e. its not a server problem).
Any ideas before I wipe and restore?