Microsoft Outlook Cannot Sign or Encrypt This Message [Error Fix]

Did you see an error stating “Microsoft Outlook cannot sign or encrypt this message”? Outlook offers strong security features to protect your emails, including the ability to sign and encrypt messages. The error message indicates a problem with your email security settings.

This action requires specific configurations and valid digital certificates. So, you’ll get this error if any of these elements are missing or incorrectly set up.

Luckily, I’ve got just the solution for it. Read on to find out!

How To Fix “Microsoft Outlook Cannot Sign or Encrypt This Message”

Follow these instructions:

Modify E-mail Security Settings

To adjust your e-mail security settings, do this:

1. Tap File in Outlook.

2. Click Options.

3. Click Trust Center and select Trust Center Settings.

4. Click the Email Security button, and ensure that the “Encrypt contents and attachments for outgoing messages” and “Add digital signatures to outgoing messages” boxes are unchecked. Tap OK.

Fix Invalid Certificate

Another issue could be that you’re using an invalid certificate. Here’s how to fix it:

1. Once you open Outlook, click File > Options > Trust Center > Trust Center Settings > Email Security.
2. Tap Import/Export.

3. Click Browse to import the digital ID from your PC.

Update Outlook

The issue could also stem from an outdated Outlook. Follow the below steps to update it:

1. Tap File.

2. Select Office Account.

3. Tap Update Options and select Update Now from the drop-down menu.

4. It’ll automatically download and install the update.

Overall, the “Microsoft Outlook cannot sign or encrypt this message” error can be frustrating, but it’s easy to resolve with the right steps. Ensure you have a valid digital certificate, modify your e-mail security settings, and update Outlook.

Another similar error includes the Microsoft Outlook was not able to create a message with restricted permission problem but we’ve already discussed how to resolve it. You may also experience App Access Blocked on Outlook.

Moreover, if you’re encountering an error related to WAB.dll, Google Workspace sync, the AutoArchive settings are greyed out, or you want to change where sent items go, we’ve got just the guides for that.

Which solution has worked for you?