Thunderbird Unable to Connect to Xfinity IMAP Server with SSL/TLS When Using Bitdefender VPN

Hello Community,

I hope someone can assist me with this persistent issue with Thunderbird while trialing the Bitdefender VPN client for my internet security. When I launch Mozilla Thunderbird, it connects to my Xfinity email account without any problems. However, Thunderbird displays an error message after a certain period, stating it can't connect to the Xfinity IMAP server. The error details suggest that the app cannot establish a connection. If I use another VPN client, I never see this issue. Since the problem does not happen during the Thunderbird's initial load, I would guess the VPN client uses IP address ranges eagerly throttled by the IMAP server's IDS/IPS algorithm.

To elaborate:

  • VPN Client: Bitdefender
  • Email Client: Mozilla Thunderbird
  • Email Provider: Xfinity
  • Error: Unable to connect to IMAP server

This connection issue disrupts my email workflow, and I can't seem to find a solution on my own. Has anyone else encountered a similar problem, or can you offer guidance on resolving this issue? As a workaround, I added a Split Tunneling exception for Thunderbird. Any insights or suggestions would be greatly appreciated.

Thank you in advance for your assistance!