Hi, @Iniobong Nkanga
Your screenshot is not quite the same as the error 2002 you said. Could you provide a more accurate screenshot?
But based on your screenshots, it looks like your users don't exist in your tenant.
Here are some suggestions you might try:
1.You can check if there are any spelling mistakes when adding an account again, and check if the user has the correct license.
2.Delete all the content in the profile folder, set up a new profile.
Depending on the error code AADSTS50020, you can refer to the following documents to fix the issue Error AADSTS50020 - User account from identity provider does not exist in tenant - Azure | Microsoft Learn
I noticed that there is the same thread as yours here, you can try the method in this thread. M365 Exchange - Microsoft Community
In addition, since the problem occurs on Outlook for Mac, and exchange online is not professional in this regard, in order to help you better, we recommend that you seek more professional help here. Contact support within Outlook for Mac - Microsoft Support
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