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How do I Send an Encrypted Email in Outlook

Published By Mohit Jha
Anuraag Singh
Approved By Anuraag Singh
Published On May 10th, 2024

This article will cover the encryption methods and features in Outlook and how to send email using encryption. It will cover two types of encryption used for emails for secure communication. And the steps to use encryption using Outlook desktop and Web application, also important points which should be considered when using encryption in Outlook 365.

Communication is a necessary aspect of any organization. Outlook is an email client widely used for communication through emails. It offers a variety of features to foster better communication and collaboration. You can set reminders and notifications for your important meetings and other events. It integrates with Microsoft apps like Word, Excel, PowerPoint, and others easily. These are secured through various encryption algorithms and  still, there are chances of security threats. So, encryption plays an important role in making communication secure. In this article, we will explore the encryption feature of Outlook and see how to send an encrypted email in Outlook.

Ways to Encrypt Emails in Outlook

There are two ways to encrypt emails in Outlook-

1. S/MIME( Digital Certificate required)

  • You must have a digital certificate to use this encryption method for your emails.
  • Certificates are used to encrypt and sign your emails digitally.
  • The certificate should be obtained from a trusted certification authority.

Steps to Configure S/MIME in Outlook

  • Sign in to your Outlook account.
  • Go to the file menu, choose options, and from options select Trust Center settings from Trust Center.
  • Choose “Settings” from under the encrypted mail option.
  • Select your signing and encryption certificate.
  • Choose OK.


  • Compose a new email in Outlook.
  • Click on options and select “Encryption” from the permission group.
  • Click send.


  • Emails can be decrypted automatically if the recipient has the private key for the received public key encrypted Outlook email.

2. Microsoft 365 Message Encryption( Requires E3 subscription plan)

  • It is part of Office 365 Enterprise E3 license.
  • You must have a Microsoft 365 Apps Enterprise subscription plan to use this feature.
  • Administrators can enable this feature to encrypt emails.


  • In Outlook, compose a new email.
  • From the permission group select “Encryption”.
  • Two options are provided here- “Encrypt Only” or “Do not Forward”.
  • Click send.
  • The specified recipients are allowed to open encrypted emails.


  • You can decrypt a received email by using your specified sender account or the one-time passcode provided to the receiver to see the encrypted Outlook email.

 Encrypt Emails Using Outlook Desktop

  1. Open your Outlook desktop app. Sign in to your account.
  2. Click on Compose to encrypt a new mail and navigate to the “Options” tab.
  3. Using the options tab. Click on “Encrypt”.
  4. Choose your encryption type according to your requirements. You will see two options- encrypt only and Do not forward.
  5. After choosing the encryption type, click send.

 Encrypt Emails Using Outlook Web App

  1. Open your browser and sign in to your account using https://outlook.office.com.
  2. Click on the new message to compose a new email.
  3. Select the encryption option and choose the type of encryption according to your needs.
  4. Choose from two encryption types- “Encrypt” or “Prevent Forwarding”.
  5. Click send after selecting the encryption type.

Also Read: How to Delegate Access in Outlook 365?

Points to Consider

  • If you want to make communication with other email providers, there might be a problem because all email providers do not use S/MIME.
  • It works well within Microsoft 365 accounts as outside users might require additional steps to decrypt the emails.
  • Use a combination of password and encryption for better security of your Outlook account.

Key Difference Between Encrypted and Non-Encrypted Messages in Outlook

Features Encrypted Non- Encrypted
Security Needs a key for decryption. As messages are in plain text and easily readable to anyone.
Data Transmission Easily encrypted during data transit between servers. It will require additional settings for encryption during transmission.
Message Forwarding Forwarding can be restricted using encryption methods.  Forward easily to anyone.
Set Permissions Easily set permissions like “Do not Copy” and others.  Users cannot set permissions.
Integration for easy decryption Specified recipients can easily decrypt messages using their Microsoft 365 emails. For decryption, recipients will require a passcode.


In this article, we learned about the encryption feature in Outlook and how to use encryption for emails. Two methods S/MIME requires a digital certificate while Microsoft 365 message encryption requires an Enterprise subscription plan to use it. Both are highly secure and provide customizable settings according to user needs. Using these approaches one can easily send encrypted Outlook email.