Error msg when trying to open saved Outlook docs

Dear Russ Sanders,

Welcome to Microsoft Q&A.

Thanks for letting us know regarding your Outlook's issues On Microsoft Office 365. Even though you have Microsoft 365, the error often appears when:

• You're using the New Outlook for Windows, which has stricter licensing checks.
• You're trying to open a .MSG file (a saved Outlook message) outside of the classic Outlook app.
• Your Microsoft 365 account is linked to a third-party email address (like Gmail or Yahoo), which may not be recognized properly by New Outlook.

Here is some workaround I hope it might help:

1. Use Classic Outlook Instead

The New Outlook version doesn’t fully support opening saved .MSG files unless certain conditions are met. Try this:

Search for “Outlook” in your Windows Start menu.

Look for the Classic Outlook app (not the one labeled “New Outlook”).

Open the .MSG file using Classic Outlook.

If you don’t see it, you can reinstall Classic Outlook.

2. Check Your Account Setup

If your Microsoft 365 subscription is tied to a third-party email.

1. Add an @outlook.com alias to your Microsoft account.
2. Set that alias as your primary account in Outlook.
3. This helps Outlook recognize your subscription properly

For your reference: https://learn.microsoft.com/en-us/answers/questions/4701629/outlook-wont-let-me-open-attached-files-saying-i-n

https://learn.microsoft.com/en-gb/answers/questions/2339617/saved-*-msg-files-wont-open-error-message-says-i-n

Please let me know if these troubleshoots and these similar situations could help you resolve anything. Thanks, and wish you all the luck!

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