How to Send Encrypted Email in Outlook

Secure Your Communication

Microsoft Outlook, one of the most widely used email clients, offers robust encryption options to ensure the confidentiality of your emails. In this comprehensive guide, we will delve into the world of encrypted emails within Outlook, how to send and receive them, and alternative methods for secure communication.

How Do I Encrypt Emails in Outlook?

When it comes to encrypting emails in Outlook, it's essential to understand the process and available options. Let's start by exploring the fundamental aspects of email encryption.

Understanding Email Encryption

Email encryption is a security measure that converts the content of your email into an unreadable format, rendering it inaccessible to anyone without the decryption key. This technology ensures that even if your email falls into the wrong hands, its content remains confidential.

Encryption Options in Outlook

Outlook offers two primary encryption methods:

  1. S/MIME (Secure/Multipurpose Internet Mail Extensions): S/MIME is a widely adopted public-key cryptography protocol. It requires both the sender and the recipient to have digital certificates. When you send an encrypted email using S/MIME, your email client uses the recipient's public key to encrypt the message, and only the recipient's private key can decrypt it.
  2. Office 365 Message Encryption: This method is more user-friendly and doesn't require recipients to have digital certificates. It utilizes Azure Rights Management to encrypt the email and any attachments, making it accessible only to the intended recipient.

How to Send Encrypted Email in Outlook?

Now that you are acquainted with the encryption options, let's explore how to send an encrypted email in Outlook using both S/MIME and Office 365 Message Encryption.

Follow these steps to send an encrypted email with S/MIME in Outlook:

  1. Install Digital Certificates: You and your recipient must have digital certificates installed in Outlook. You can obtain these certificates from a trusted Certificate Authority (CA).
  2. Compose Your Email: Create your email as you normally would.
  3. Enable Encryption: Click on the "Options" tab in the message window and select "Encrypt."
  4. Send Securely: Once you've enabled encryption, click "Send." Your email will now be encrypted using the recipient's public key. And the recipients cannot remove the encryption.

If you prefer a more straightforward encryption method, Office 365 Message Encryption is the way to go:

  1. Compose Your Email: Start by composing your email as usual.
  2. Encrypt Email: In the email composition window, click the "Encrypt" button as before. This action will encrypt both the email content and any attachments.
  3. Set Permissions: You can further control who can access the email by setting permissions. This step is optional but adds an extra layer of security. You can restrict access to specific recipients or require them to authenticate their identity.
  4. Send Securely: After configuring your preferences, click "Send." Your email will now be protected by Office 365 Message Encryption.

As technology becomes more accessible to every corner of the world, cybercriminals also learn to break through this basic security wall. It is when you need to rely on a much more advanced technological solution for your email's security.

For example, RMail is one such secure email service that runs inside Microsoft Outlook and leverages AI to offer enhanced protection over and above Outlook’s built-in protection. It comes with advanced data loss prevention, smart encryption, and futuristic pre-crime technology.

How do I Read an Encrypted Email Message?

Receiving an encrypted email in Outlook is a straightforward process. When someone sends you an encrypted email, you will receive a notification indicating that the email is protected. Here's how to read it:

  1. Depending on the sender's settings, you may be required to authenticate your identity to access the email. This can be done by entering a one-time code sent to your email or other verification methods.
  2. Once authenticated, you can read the email as you normally would. Outlook will automatically decrypt the message and any attachments, making them accessible.

How Is This Different from the Current Level of Encryption in Outlook Web?

Outlook, the web-based email service by Microsoft, offers a baseline level of encryption to protect your emails during transmission. However, this level of encryption primarily safeguards your messages in transit and at rest on Microsoft's servers.

The encryption methods discussed earlier, S/MIME and Office 365 Message Encryption, provide an additional layer of security by encrypting the email content itself. This means that even if someone gains unauthorized access to your email account, they won't be able to read the encrypted messages without the decryption keys.


Q: Can I send encrypted emails to anyone in Outlook?

For S/MIME encryption, both the sender and recipient must have digital certificates. However, Office 365 Message Encryption is more versatile and allows you to send encrypted emails to recipients without digital certificates.

Q: Is email encryption in Outlook available for all versions of the application?

S/MIME encryption is available in most versions of Outlook, while Office 365 Message Encryption is primarily designed for Office 365 users. Make sure your version of Outlook supports your chosen encryption method.

Q: How can I obtain digital certificates for S/MIME encryption?

You can obtain digital certificates from trusted Certificate Authorities (CAs). These certificates are typically issued after verifying your identity.