You need to send sensitive information like financial data or personal details via email. Microsoft 365 Message Encryption protects your message content from being read by unintended recipients. This article provides the steps to encrypt a single email directly from Outlook on the web or desktop.
Key Takeaways: Sending Encrypted Email in Outlook
- Encrypt button in Outlook on the web: Applies the default encryption template to a new message with one click.
- Options > Encrypt in Outlook desktop: Access encryption settings from the message ribbon to choose a protection template.
- Do Not Forward permission: Prevents recipients from forwarding, copying, or printing the encrypted email content.
Understanding Microsoft 365 Message Encryption
Microsoft 365 Message Encryption is a service included with certain Microsoft 365 subscriptions. It uses Azure Rights Management to protect email content. The encryption works whether the recipient uses Outlook, Gmail, Yahoo, or another email service.
When you send an encrypted message, the recipient receives a notification. They can view the message in a secure web portal by signing in with a Microsoft account, a one-time passcode, or their work account. Your organization’s administrator must enable this feature and may configure default policies.
Prerequisites for Sending Encrypted Email
You need a Microsoft 365 plan that includes Azure Rights Management, such as Office 365 E3, E5, or Microsoft 365 Business Premium. Your IT administrator must have activated the service. You must be signed into Outlook with your work or school account. Personal Microsoft accounts like Outlook.com cannot send encrypted emails using this enterprise service.
Steps to Encrypt an Email in Outlook on the Web
The Outlook web app provides a simple interface for applying encryption. The Encrypt button applies your organization’s default protection policy.
- Compose a new email
Open Outlook on the web in your browser. Click New message to start composing your email. - Click the Encrypt button
In the message composition toolbar, locate and click the lock icon labeled Encrypt. This button is usually next to the Send button. - Verify the encryption notice
A message appears below the recipient fields stating “This message is encrypted.” This confirms the protection is active. - Send the email
Finish writing your subject and message body. Click the Send button to deliver the encrypted email.
Steps to Encrypt an Email in Outlook Desktop for Windows
The Outlook desktop application offers more granular control over encryption options through the Options tab on the ribbon.
- Create a new email
Open Outlook and click New Email to open a message window. - Go to the Options tab
In the new message window, click the Options tab on the ribbon at the top. - Click the Encrypt button
In the Permission group, click the Encrypt button. A dropdown menu will show available protection templates. - Select an encryption option
Choose an option like Encrypt-Only or Do Not Forward. Encrypt-Only protects content but allows forwarding. Do Not Forward adds restrictions. - Complete and send the message
Add your recipients, subject, and message body. Click Send to dispatch the encrypted email.
Common Mistakes and Limitations to Avoid
Encrypt Button Is Missing or Grayed Out
If the Encrypt option is unavailable, your Microsoft 365 subscription might not include the service. Contact your IT department to verify licensing. Another cause is using a personal Microsoft account instead of a work or school account. Ensure you are signed into the correct account within Outlook.
Recipient Cannot Open the Encrypted Message
Recipients might not see a “View Message” button if their email client blocks external images. Instruct them to check their spam folder or enable images in the email. If they are prompted for a passcode but do not receive it, ask them to check their email’s junk folder for the Microsoft encryption message.
Encryption Does Not Apply to Attachments in Forwarded Messages
If you forward an encrypted email, the original encryption does not automatically apply to new attachments you add. You must apply encryption again to the new forwarded message. Always use the Encrypt button on the new message you are sending.
Encryption Options in Microsoft 365 Message Encryption
| Item | Encrypt-Only | Do Not Forward |
|---|---|---|
| Primary Use | Protect message content in transit and at rest | Restrict what recipients can do with the content |
| Recipient Actions | Can forward, copy, and print the message | Cannot forward, copy, print, or take screenshots |
| Best For | Sending confidential data to trusted partners | Sending highly sensitive data like contract terms |
| User Experience | Recipients view message with minimal restrictions | Recipients see a more restricted viewing portal |
You can now send secure emails using Outlook encryption. For broader policy control, ask your admin about setting up automatic encryption rules in the Microsoft 365 admin center. A useful advanced tip is to create a Quick Step in Outlook desktop to apply encryption to messages with a single keyboard shortcut.