Using Classic Outlook on Windows for personal email, calendar, and contact management
@Vidya Pingili said
after entering the correct password, Outlook reconnects only temporarily
1 -- Any clues in the Sync Issues Folders?
How to View the Sync Issues Folders in Classic Outlook
See the Answer by "Hornblower409 May 6 2026" in
https://learn.microsoft.com/en-us/answers/questions/5687493/outlook-how-to-view-and-cleanup-sync-error-folder
2 -- Can you correlate the disconnects to an Outlook action? e.g. As soon as your do a Send, or a Send/Receive All (F9)?
3 -- Any other email clients connected to the same account? (IONOS server connection limits)
I would appreciate it if the underlying cause of the authentication or connection issue could be investigated
For that you'll have to bring in Microsoft Support.
MS 365 Admin Only Support (Qualified MS 365 Subscriptions only)
https://learn.microsoft.com/en-us/microsoft-365/admin/get-help-support
Free Classic Outlook In App Support
Help -> Contact Support