Troubleshooting email client warnings about invalid server certificates

Follow the steps below to stop warnings about invalid mail server certificates. You must first export the Email Protection certificate, then import it into your email client's certificate store.

Export the Email Protection certificate

1. On your keyboard, press the Windows logo key and the E key simultaneously to open Windows Explorer.
2. Navigate to the following location:
   C:/ProgramData/Norton/AntiVirus/
   

   The ProgramData folder could appear hidden. To display hidden files and folders, refer to the following article: Microsoft Support > File Explorer in Windows.

3. Find the following certificate file:
   wscert.der
4. Copy and save the file on your desktop.

The Email Protection certificate has been exported. Follow the instructions below to import it into your email client.

Import the Email Protection certificate to your email client

1. In Mozilla Thunderbird, click the menu icon (the three lines) > Settings.
2. On the left panel, select Privacy & Security.
3. Scroll down to the Certificates section, and click Manage Certificates.
4. In the Authorities tab, click Import.
5. Locate the wscert.der file that you saved on your desktop, select the file, then click Open.
6. In the alert that appears, tick the box next to Trust this CA to identify websites, and click OK.
7. When the Certificate Manager screen appears again, click the Servers tab.
8. Ensure that there is no entry for Norton Email Protection. If an entry exists, delete all certificates connected to Norton Email Protection in the Servers tab. Then, click OK to save the changes.

The Email Protection certificate from Norton is now imported to Mozilla Thunderbird.

If you see certificate warnings or errors in Microsoft Outlook, we recommend you reinstall your Norton application:

1. Use the Norton Remove and Reinstall tool for Windows to uninstall your Norton application. Choose Remove Only from the Advanced Options menu. For detailed instructions, follow these steps: Download and run the Norton Remove and Reinstall tool for Windows.
2. Before reinstalling your Norton application, open Microsoft Outlook and check if the issue persists:
   • If the problem still occurs, it is likely not caused by Norton. In this case, check your email account settings in Outlook and ensure they are configured correctly according to your email provider’s instructions.
   • If the problem does not occur, proceed to the next step and reinstall Norton application.
3. Reinstall your Norton application.
4. Restart your Windows device again.

Once your Norton app is reinstalled, open Microsoft Outlook and check if the issue persists.