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Troubleshooting email client warnings about invalid server certificates

After installing AVG Internet Security or AVG AntiVirus FREE some 3rd-party email clients, such as Mozilla Thunderbird, SeaMonkey, or The Bat!, may show that the email server certificate is invalid when you send and receive emails.

The AVG Email Shield uses an advanced scanning method for incoming and outgoing emails over SSL/TLS secured connections. Mozilla Thunderbird, Sea Monkey, and the Bat! have their own certificate stores and may require extra configuration to avoid warnings about invalid Email server certificates.

Refer to the sections in this article for instructions on how to stop warnings about invalid Email server certificates by exporting the Email Shield certificate and importing it into your email client's certificate store.

Export Email Shield certificate

  1. Open the AVG user interface and go to MenuSettings.
  2. Click the Search icon in the top-right corner.
  3. Type geek:area into the text box that appears, and select AVG Geek from the search results.
  4. Scroll to the Email Shield section. Ensure the box next to Scan SSL connections is ticked, then click Perform next to Export certificate.
  5. Select a location to save the exported Email Shield certificate (for example, your Windows Desktop) and click Save.
  6. Click OK in the AVG Information dialog.
  7. Import the Email Shield certificate into your Email client.
Each email account in your Email client needs to be configured as required by your Email provider. Refer to your Email client's and Email provider's documentation for instructions.

Import Email Shield certificate

  1. In Mozilla Thunderbird, click Menu (three lines) and select Options twice.
  2. Select the Advanced tile.
  3. Select the Certificates tab and click Manage Certificates to open the Certificate Manager.
  4. Select the Authorities tab, then click Import.
  5. Locate the Email Shield certificate you exported from AVG Internet Security or AVG AntiVirus FREE, then select the file and click Open.
  6. Tick Trust this CA to identify websites and click OK.
  7. In the Certificate Manager dialog, select the Servers tab and ensure that there is no entry entitled AVG Email Scanner.
    • If this entry exists, delete all certificates connected to AVG Email Scanner on the Servers tab by selecting all connected certificates, clicking Delete, and then clicking OK to confirm.
  8. Click OK in the Options dialog to apply the changes.
  1. In SeaMonkey, click Edit at the top of the screen and select Preferences....
  2. Click the arrow next to Privacy & Security to expand this section.
  3. Select Certificates and click Manage Certificates....
  4. Select the Authorities tab, then click Import....
  5. Locate the Email Shield certificate you exported from AVG Internet Security or AVG AntiVirus FREE, then select the file and click Open.
  6. Tick Trust this CA to identify websites and click OK.
  7. In the Certificate Manager dialog, select the Servers tab and ensure that there is no entry entitled AVG Email Scanner.
    • If this entry exists, delete all certificates connected to AVG Email Scanner on the Servers tab by selecting all connected certificates, clicking Delete, and then clicking OK to confirm.
  8. Click OK in the Preferences window to the apply changes.
  1. In The Bat!, click Tools at the top of the screen, and select Address Book.
  2. Click View and select Certificate Address Books.
  3. Right-click Trusted Root CA and select New Contact from the context menu.
  4. Type AVG Email Scanner Root in the First name field and click OK.
  5. Select the Certificates tab and click Import....
  6. Locate the Email Shield certificate you exported from AVG Internet Security or AVG AntiVirus FREE, then select the file and click Open.
  7. Once the Email Shield certificate is imported, click OK to apply the changes and exit the Address Book.
  • AVG Internet Security 20.x
  • AVG AntiVirus FREE 20.x
  • Microsoft Windows 10 Home / Pro / Enterprise / Education - 32 / 64-bit
  • Microsoft Windows 8.1 / Pro / Enterprise - 32 / 64-bit
  • Microsoft Windows 8 / Pro / Enterprise - 32 / 64-bit
  • Microsoft Windows 7 Home Basic / Home Premium / Professional / Enterprise / Ultimate - Service Pack 1, 32 / 64-bit

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