Encrypted Error Message

Question

I can send encrypted emails; however, when opening them, I am getting an error message. I sent a test one to myself and am getting the same message. What do I do?

Answer 1

Hi Kimberley Koenig

Thank you for reaching out to the Microsoft Q&A forum. I understand you can send encrypted emails from Outlook.com, but when you try to open the encrypted email, you get an error message. 

Please paste the exact error message text you see when opening the encrypted email (or share a screenshot with any addresses/IDs hidden) and confirm whether the encrypted email appears as a normal message in Outlook.com or as an attachment like message.html.  

Meanwhile, follow these steps if you have tried the AI given steps but do not work:  

• Open the encrypted email in a new window 
  • Encrypted messages may show restricted-permissions info in the reading pane. Open the message in a new window to view it normally.  
• If the encrypted email shows an attached file like “message.html”, open that attachment and use the sign-in flow 
  • Some encrypted messages are delivered with an attachment (for example message.html) and you open it, then select “Sign in and view your encrypted message” to view the content.  
• Try opening the same encrypted email in another supported Outlook client  
  • Test in Outlook mobile and confirm whether this is a browser/session-specific issue vs. an account issue. 
• Confirm you are using an encryption option supported for Outlook.com (Microsoft 365 Personal/Family) 
  • Outlook.com users with Microsoft 365 Personal/Family can use Encrypt or Do Not Forward, and recipients using Outlook.com/Microsoft 365 can read encrypted messages in Outlook.com or Outlook mobile like normal. If your account is in this category, the encrypted message should typically open directly in Outlook.com. See: Send encrypted messages with a Microsoft 365 personal or family subscription - Microsoft Support 
• If it still fails 
  • Use Troubleshoot Office 365 message encryption - Microsoft Support (and proceed based on what the message contains and what you see).  

Please tell me how it goes. If the problem persists, please don’t hesitate to reply to this thread and I will be happy to help. Have a lovely day!   

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Answer 2

Follow these steps to troubleshoot encrypted email open errors in Outlook on the web/Outlook.com:

1. Verify basic connectivity and message format
   • Make sure the device is connected to the internet by opening a website in a browser.
   • Open the encrypted message and confirm there is a “Read the message” link in the body. If that link is missing, the message may not be a valid Office 365 encrypted message; in that case, contact the sender (even if it is the same account) and have a new encrypted message sent.
2. Test with a new encrypted message
   • Compose a brand‑new email (do not reply or forward an existing one).
   • Add a normal text body and subject.
   • Apply encryption as usual and send it to the same mailbox.
   • Open the received message and use the “Read the message” link if present.
3. If the problem persists across devices and browsers
   • If encrypted messages cannot be opened in any browser or device, and test messages to self fail in the same way, the issue is likely with the account’s encryption configuration on the service side rather than the local setup.
   • In that case, contact Microsoft support and ask them to check the account’s Office Message Encryption (OME) configuration and status.

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References:

• Troubleshoot Office 365 message encryption
• Unable to send encrypted emails in Outlook for Mac and Outlook.live.com (admin account) since 03/13 - Microsoft Q&A