Encrypt email with Advanced Email Security
Keep your sensitive information secure with email encryption. When you send email to external recipients, Advanced Email Security hosts the message in the encryption portal where only the sender and the intended recipient can access and view it.
Note: Microsoft 365 automatically encrypts email sent within your organization. You only need to manually encrypt your email when sending to external recipients like a client or vendor.
Send encrypted messages
Send an encrypted message by adding [encrypt] at the beginning of its subject line. This works on any email client and on any device, including mobile.
After sending the message, you'll receive a confirmation email letting you know the encrypted message was successfully sent.
To see the message, select View Encrypted Message. You may see options to sign in to the encryption portal. Select Sign in with Microsoft to enter your email address and password. Or, select Sign in with email to receive a link in your email and sign in without having to provide a password.
Receive encrypted messages
The recipient will get an email from your email address letting them know they've been sent an encrypted message. To access the message, they'll need to select View Encrypted Message.
They'll see a page where they can sign in to the encryption portal. They can sign in with their existing Microsoft or Google account. Or, they can select Sign in with email to receive a link in their email. This option allows them to sign in without requiring a password.
View the encrypted message
Once signed in, you'll see a list of messages on the left. All sent and received messages will appear in this list sorted by date. Select a message to decrypt it and view it.
Select Reply to send a response. Your response can include attachments and HTML elements. Secured messages can't be forwarded or saved locally.
Note: Any responses to encrypted messages from Microsoft 365 users will appear in their inbox unless the message or its attachments are larger than 20 MB. In that case, the user will receive an email notification so they can sign in and view the response in the message list.
Limitations for encrypted messages
There are some limitations to keep in mind when sending and receiving encrypted messages with Advanced Email Security:
- Encrypted outbound messages must be less than 75 MB including attachments.
- Replies in the encryption portal must be less than 75 MB including attachments.
- Encrypted messages will only be retained for 30 days.
Microsoft 365 limitations still apply.