Hi, @Lesley Moore
Based on your description, I understand that the email is still on the server, but it is not showing up in the inbox correctly.
You can troubleshoot by following these steps:
- Does the issue exist in the Outlook client and OWA?
- Check your email filters and sorting options to see if they have custom filtering options set up like "Unread", "Starred", etc. For more information, see Items disappear or are not visible in an Outlook folder - Outlook | Microsoft Learn
- Try to rebuild the email index. Fix search issues by rebuilding your Instant Search catalog - Microsoft Support
- Open Outlook in Safe Mode to exclude the interference of add-ins.
- Create a new Outlook profile to see if the problem exists. Create an Outlook profile - Microsoft Support
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