Using New Outlook on Windows for personal email, calendar, and contact management
Hi! Sorry to hear you're having trouble. Have you tried removing the account from the Outlook app and then adding it again?
- Open Gmail on the web (mail.google.com).
- Search for the subject of one of the “stuck” replies.
- Check Sent and also All Mail. If you find the message in Sent/All Mail, then it was sent and this is a New Outlook/Gmail sync/state bug.