Hi @MD53 ,
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What's the version of your Outlook? (File > Office Account > About Outlook). Please make sure you have upgraded your Outlook to the latest version.
In order to further confirm if your issue is related to your client or mailbox, please log in to your web mail to check if the issue could be reproduced there.
If the issue occurred on Outlook only, can you find it after searching for subject or other details?
Try to clean view settings: Open Run by pressing Windows + R keys at the same time.
Enter the following command in Run and press Enter to reset Outlook’s viewing pane settings: outlook.exe /cleanviews
Besides, corrupted Outlook profile can also lead this issue, so please try creating and using a new Outlook profile via Control Panel > Mail > Show profile > Add and see if there is any difference.
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