Encrypt messages with Advanced Email Security
Microsoft 365 automatically encrypts all messages sent within your organization. To protect any sensitive information when sending to external recipients, like customers or vendors, you need to manually encrypt your email. With Advanced Email Security, an encryption filter is already built in — which means all you need to do is edit your message's subject line to encrypt it.
- If you’re using Advanced Email Security from Proofpoint, there will be a header with “GoDaddy."
- If you’re using Advanced Email Security powered by INKY, there will be a header that includes "Powered by INKY."
Send an encrypted message
To encrypt an email, add [Encrypt] at the beginning of the subject line. This works on any email client and any device.
![An example of a message with [Encrypt] in subject line.](https://images.ctfassets.net/7y9uzj0z4srt/8p9xNwGbstHIbMZoiiaBw/35543a7cb5fea9b17639a916cda58cde/O365-Encrypt-in-subject-line-01.png)
After sending the message, you'll receive an email confirming the message was encrypted.
The recipient will receive an email with instructions on how to sign in to Advanced Email Security to view and respond to the encrypted message. The email expires after 15 days and the recipient cannot forward or save it (but they can download attachments from the email).
View an encrypted message that was sent to you
When you receive an encrypted message, you’ll receive an email notification (you'll see the subject line "You have received an encrypted email"). To view the message, select View Encrypted Email, and then sign in to the encryption portal. You'll need to register and verify your email address if you don't have an account.
You'll see a list of sent and received messages, sorted by date, on the leftmost side when you're signed in. Select a message to decrypt it and view it. To send a response, select Reply.
Limitations for encrypted messages
Keep the following limitations in mind when sending and receiving encrypted messages with Advanced Email Security from Proofpoint:
- Encrypted outbound messages must be less than 35 MB, including attachments.
- Encrypted outbound messages can only have up to 256 files attached.
- By default, Advanced Email Security keeps encrypted messages for 15 days.
Microsoft 365 limitations also still apply.
Send an encrypted message
To encrypt an email, add [encrypt] or (encrypt) at the beginning of the subject line. This works on any email client and on any device.
![[encrypt] in subject line](https://images.ctfassets.net/7y9uzj0z4srt/4uEWcbTJ7Rgyojdan3E7zq/68724d6324fb7b6bfded3ac3ea191654/image-article-40970-01.png)
After sending the message, you'll receive an email confirmation. Select View Encrypted Message to see the message. You might need to sign in to the encryption portal.
The email expires after 15 days and and the recipient cannot forward or save it (but they can download attachments from the email).
View an encrypted message that was sent to you
When you're the recipient of an encrypted message, you’ll receive an email notification addressed from Proofpoint Essentials on behalf of the sender. To access the message, select View Encrypted Message. You'll need to sign in to the encryption portal.
To sign in with an existing email account, select Sign in with Microsoft or Sign in with Google. Or, you can select Sign in with email to receive a link in your email. This option allows you to sign in without using a password.
You'll see a list of sent and received messages, sorted by date, on the leftmost side when you're signed in. Select a message to decrypt it and view it. To send a response, select Reply.
Limitations for encrypted messages
Keep the following limitations in mind when sending and receiving encrypted messages with Advanced Email Security powered by INKY:
- Encrypted outbound messages must be less than 75 MB, including attachments.
- Replies in the encryption portal must be less than 75 MB, including attachments.
- By default, Advanced Email Security keeps encrypted messages for 30 days.
Microsoft 365 limitations also still apply.
More info
- What is Advanced Email Security?
- Learn more about linked domains and organizations in Microsoft 365.
- What do the banners from Advanced Email Security mean?
