How To Read Encrypted Mail from Office 365

Some Outlook clients are able to receive encrypted messages, and will not require the use of the encrypted message portal or Outlook Web Access; however, the Outlook Web Access application is the recommended and easiest method to view these messages.


Reading Messages From Outlook Web Access:

If you receive an encrypted message and you’re in Outlook Web Access, OME will automatically decrypt the message.

A banner will appear under the sender’s information and above the email body describing the permissions set on the message. No further action is required.

The encrypt banner is displayed.


Reading Messages From Outlook:

If your Outlook client is unable to decrypt the message, an encrypted message will read “Sender (sender’s email address) has sent you a protected message.”

Option 1 (preferred): Go directly to OWA by going to and sign in to your Office 365 account. Do not click on links in the email. This protects your account from phishing attacks. If the message is legitimate, it will be viewable as per the steps above.

Option 2: Under the “sender has sent you a protected message” text, there will be a link to “Read the message.” Click “Read the message.”

If you are already logged into your LSU Office 365 mail account in your web browser, the message will open in your browser with no further action required.

If you are NOT currently logged into your Office 365 account, you will be brought to the Microsoft login page. Make sure you’re logging into the real Office 365 site by verifying the URL is Do not provide your login information if the page is not at Report the message as phishing if you are brought to another sign on page.

The encrypted message will be available for viewing in your browser window after you sign in.


Reading Messages From an External (Non-LSU Account):

If you have received an encrypted message from LSU, you may need to sign into the Office 365 Protected Message Viewer Portal to view your email.

You will receive a message that says “Sender (sender’s email address) has sent you a protected message.”

Click the link to “Read the message.”

You will be brought to a page on that provides two options to sign in and view the message.

  • If your email provider allows it, you can sign in directly with your Google, Yahoo, Outlook, etc account. This allows Office 365 to check with your email provider directly to verify that you have access to the receiving account and should be allowed to view the protected email. Microsoft does NOT collect or process your login information, only your email provider receives and validates your login.
  • You can select to sign in with a one-time passcode. A second message will be sent to your email address with a special code. Input this code into the next screen to access your message.

If you are unsure of the validity of an email, the sender’s information should be present in the message. Send a new, separate email directly to the sender to verify that they have sent you an encrypted message before proceeding if something doesn’t seem right.


Accessing Attachments on Encrypted Messages

An encrypted message may contain attachments.

You can click the attachment in OWA, the Protected Message Viewer Portal, or supported mail client to view the file within the browser or client. 

Depending on the file type, downloading the file may be restricted. It is suggested to use the file preview in OWA or the viewing portal to access encrypted attachments. 


Referenced from: Microsoft Office Support

4/17/2024 8:32:46 AM