How to Open Encrypted Emails
A message that is encrypted by Microsoft Purview Message Encryption is delivered to your inbox just like any other email message. If you're using Outlook, you'll see an alert about the item's restricted permissions in the Reading pane near the message header. Open the message in a new window to view the message just like any other.
Messages that have the encrypt-only policy applied can be read directly in new Outlook, Outlook on the web, Outlook for iOS and Android, Outlook for Windows versions 2019 and newer, and Microsoft 365. If you're using another mail service, you'll see a message with a link. That link will take you to either to Outlook on the web if you're a Microsoft 365 subscriber, or you'll be prompted to get a one-time passcode to read the message in a browser window.
View and reply to an encrypted message
If you're in a Microsoft 365 organization, you can read messages encrypted with the encrypt-only or do-not-forward policies, or custom protection templates. You won't be able to reply if the sender applied a Do Not Reply policy to it.
To reply to an encrypted message
Choose Reply or Reply All.
On the page that appears, type a reply and choose Send. An encrypted copy of your reply message is sent to you.
View and reply to an S/MIME encrypted message in Outlook
A lock icon on the incoming mail will suggest email is encrypted. If S/MIME encrypted, Outlook will check whether there is a certificate available on your computer. You might have to give access to the Keystore if required.
If there is a certificate available, the message will be decrypted when you open it. If your certificate is stored on a smart card, you'll be prompted to insert the smart card to read the message. Your smart card might also require a PIN to access the certificate.
Note: If you're using Outlook on desktop, on the web, or Outlook mobile, you'll have to open the message in a new window to read it. Conversation view does not support viewing encrypted messages.
View and reply to an encrypted message in another email service, like Gmail or Yahoo
If you're using Outlook without Microsoft 365, your encrypted message will contain a link in the message body.
Select Read the message.
Select how you'd like to sign in to read the message. If your email provider is Google, Yahoo, or Microsoft, you can select Sign in with Google, Yahoo, or Microsoft respectively. Otherwise, select sign in with a one-time passcode.
Once you receive the passcode in an email message, make a note of the passcode, then return to the web page where you requested the passcode and enter the passcode, and select Continue.
Tip: Each passcode expires after 15 minutes. If that happens, or if you can't open the message for any reason, start over by opening the attachment again and following the steps.
Verify an S/MIME signature of a digitally signed message
A ribbon icon in the message list or reading pane indicates a digitally signed message. Information about the digital signature will be at the top of the message, along with a link that you can select to learn more about the digital signature.
Notes:
In new Outlook, if you normally use conversation view, you'll have to open the message in a new window to read it.
Currently, new Outlook does not automatically install digital IDs, or certificates, you can either install the certificate manually or ask your administrator to configure policies to automatically install a certificate.
Open protected emails
Protected messages allow the sender to set specific permissions on a message, such as Do Not Forward or Do Not Print. If you receive a protected email message sent to the work or school account you use with Microsoft 365 in any Outlook platform, the message should open like any other message. You'll see a banner at the top of the message that informs you of any restrictions on the message.
If you're using a different email account or email program, you may receive a notification that you've received a protected message and need to take additional action.
Read a protected message in Outlook
If you're using a work or school account with Microsoft 365 in any desktop or online version of Outlook (new or classic Outlook, Outlook for Mac, Outlook on the web or Outlook.com) you shouldn't have to do anything special to read your message.
Read a protected message with Gmail
Desktop/Browser:
Open the message.
Select Read your message.
Select Sign in with Google.
You'll be redirected to the Gmail sign-in page. Once you sign in, select Allow.
Your protected message will display in a new browser tab. You won't be able to view the protected message in the Gmail window.
Read a protected message with a single-use code
Some email clients and services can't automatically open protected messages. If you have an email account with Yahoo or other Internet Service Provider, you'll need to obtain a single-use code to read the message.
Desktop/Browser:
Open the message.
Select Read the message.
You'll be redirected to a page where you can sign in and receive a single-use code.
Check your email for the single-use code. Enter the code in the browser window, then select Continue to read your message.