Invalid Security Certificate Error when using AVAST
If you use Avast anti-virus software, you may see an error message about an invalid security certificate when you're setting up a google account or when you're fetching mail from a google account.
The issue is one of Avast's Mail Shield settings that scans connections which use the SSL security protocol. Since SSL provides a secure connection, this feature of Avast offers extra protection for connections that should already be secure.
To solve the invalid certificate issue:
- Launch Avast.
- Click SETTINGS, and then select the Active Protection tab.
- Click Mail Shield's Customize button to display the SSL Scanning window.
- Uncheck Scan SSL connections.
- Exit Avast.
Alternatively, some customers report that they've been able to add IMAP servers to NOT scan, which could also solve the problem.