How to encrypt Emails in Microsoft Outlook app and

How to encrypt Emails in Microsoft Outlook app and, you can do so using a secure connection. The process is different, however. Here we are talking about email encryption and not the connection. You can think of it as an extra layer of protection.

How to Password-protect Emails in Outlook

While it is easy to use, keep the end-user and client in mind. Unless both the sender and receiver support the encryption format, it will be challenging to send email.

There are two types of Encryption supported by Outlook—

  • S/MIME encryption, and
  • Office 365 Message Encryption.

The later only works when a business uses the Office 365 Enterprise E3 license. The former, however, is widely used and works with most Outlook alternatives. Outlook Web offers in-house encryption, which you can choose to enable for individual emails. In this topic, we will discuss the following things:

  1. How to encrypt Office Outlook Emails
  2. How to Encrypt Outlook Web Emails
  3. How to read Encrypted email outside Office Clients

Note: There is no way to password-protect individual or emails in Outlook. You can, however, password protect the PST files, so all your emails are not accessible by anyone. This is different from encryption.

How to encrypt emails in Outlook on Windows 11/10

Before we start, if you want to use S/MIME encryption, both the sender and recipient will need to have a mail application that supports the S/MIME standard. Outlook supports the S/MIME standard. You can either choose to encrypt all emails, or just individual emails – it all depends on the policy enforcement of the IT department. Also, you’ll need to have an S/MIME certificate installed. Make sure to connect with the right person to do so. Once installed, you’ll have the option available in the digital certificate dropdown in Outlook.

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Encrypt Individual Email

  • In the New Email composer, go to the Options tab.
  • Click on the arrow at the bottom right to expand the More options section.
  • It will open the Properties section. Click on the Security Settings button.
  • The email will be encrypted using this standard.

Note: If you have not already done so, Outlook will prompt you to add an S/MIME certificate before you can send an encrypted email.

Encrypt all the Emails

  • Open Outlook and click the “File” menu.
  • Click on Options, and navigate to Trust Center > Trust Center Settings > Email Security.
  • Please ensure that the “Encrypt message contents and attachments” option is checked.
  • Go to Settings > Certificates and Algorithms > select the S/MIME certificate.
  • Choose OK

When you enable S/MIME encryption for your email, the recipient will need to have a compatible email client to read the message.

How to encrypt emails in Outlook on the Web

This feature is available only to Office 365 Home or Office 365 Personal subscribers. It helps when you’re worried about the security of the recipient’s email provider. But be sure you understand how it works, or the person you’re sending to won’t be able to read your email or access its contents.

Log in to the Outlook account, and then click on the new message button.To encrypt an email in Outlook, log in to your account and click the new message button. Then, next to the Attach button, click Encrypt. You will have two options:


  • The message remains encrypted and does not leave Office 365.
  • and Office 365 users can download attachments without encryption.
  • “They” can access, the Outlook mobile app, or the Mail app in Windows 10 using their Microsoft account.

If they are using any other email client, they will have to use a temporary passcode to download the attachments from the Office 365 Message Encryption portal.

Encrypt and Prevent Forwarding:

  • The message stays encrypted in Office 365.
  • This message cannot be copied or forwarded.
  • Documents that are encrypted in an office format, such as Word or Excel, will remain encrypted even after they are downloaded.
  • Attachments such as PDF files or image files can be downloaded without encryption.

How to read encrypted email outside Office clients

If you want others using apps like Gmail to read your encrypted email, then you need to share the method discussed below. This method will ask for a password to access the email, but it’s a passcode offered by Microsoft to check the authenticity of the receiver.

  • Encrypt your email before sending it to make sure it can’t be read by anyone except the intended recipient.
  • The person will get an email that will reveal information about his/her email id.
  • Then to read the message, click on Read the Message button
  • It will take you to the Office 365 center where you can verify your identity using either a One Time passcode or by signing into your Google account.

The email never leaves Office 365 servers. It is hosted there and allowed to be read after verification. If you are using an Outlook client, you will not have to go through the process.

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