Hi @Lindsay Lugar
According to my tests, pictures copied from Outlook emails can be pasted into Teams messages normally. Please check if the issue can be reproduced on Teams web.
If you can successfully use this function in Teams on the web, it means that there is something wrong with your client. You can try the following suggestions to check if the issue can be solved.
1.Clear Teams cache:
2.Update your Teams if your version is not the latest.
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