Hmm, I had a similar issue. Are you sure your proxy server isn’t blocking the connection? Some proxies have strict rules for email traffic.
Also, try using a VPN instead of a proxy. It’s way easier to set up and works seamlessly with Thunderbird. I switched to [VPN Name], and it solved all my Gmail proxy over Thunderbird problems.
Also, try using a VPN instead of a proxy. It’s way easier to set up and works seamlessly with Thunderbird. I switched to [VPN Name], and it solved all my Gmail proxy over Thunderbird problems.