Hi @Mina Carroll , thanks for posting in our Q&A forum.
Have you followed Turn new message alert pop-up on or off - Microsoft Support?
Given your situation, we suggest you try below methods:
1: Search Settings in the search bar of Windows, go to Notification & actions, make sure you have enabled notifications for Outlook.
2: Check the Rule for email notifications in Outlook: Click Rules > Manage Rules & Alerts**.**
3: You can try to create a new profile to see the result.
4: Can the address receive emails normally? if not, check if your license expired.
if issue persists, please provide your outlook version, for instruction please check What version of Outlook do I have?
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