Q: What OS are you using ? Q: What version of Thunderbird? Q: What VPN provider?

Please post information on current setup.

• Help > Troubleshooting Information
• Do not select the checkbox that says 'Include account names'.
• Click on on 'Copy Text to clipboard'
• Paste the info into this forum question.

re :all of a sudden it stopped working this morning. Q: Did you get any updates for Thunderbird or Anti-Virus etc? When you start Thunderbird, what does it say in the bottom Status bar about connecting to server? Q: Do you get any error messages ? If yes, post image or state word for word what error you get.

• Tools > Developer Tools > Error console
• Click on the 'Bin' icon to clear.
• Exit Error console
• Exit Thunderbird
• STart Thunderbird
• open 'error console' again

Q: What does it contain ? Post image.

If you are using it at home, this could be a VPN issue. Perform Test: Restart computer in 'Safe Mode with Networking' and then start Thunderbird. Q: What was the result of the test? If this works ok then you know the issue is possibly with the Anti-Virus. As the Anti-virus may also control the Firewall, check the Firewall is not blocking ports.

If an update in Thunderbird occured, it is possible the Firewall thinks this is a different program. The Firewall should list Thunderbird as an allowed program. TEST Firewall settings:

• Exit Thunderbird.
• Access Firewall.
• If Thunderbird is not listed then add to list.
• If it is already listed and allowed, then block/remove, ok it. Access Firewall again and allow Thunderbird and ok it.

This is just to ensure, Firewall is allowing current Thunderbird. Start Thunderbird. Q: What was the result of the test?

It is also important to make sure the VPN provider is also not blocking the ports you need to access the mail server.

@Ryonan, Do I take your lack of a reply as a lack of time to reply, or you have found a solution? Toad asked me to look at this, but really I can add very little here. A sudden failure without some change to the software (Thunderbird) it is really very unlikely to be the software that causes the issue.

One that can trick many is many business VPN's actually authorize a range or a collection of IP addresses to connect. Even though your IP address allocated by your ISP may be stable for long periods (Some US providers approach fixed), unless your product with them offers a fixed IP it can change without any form of notice rendering the VPN entirely inaccessible.

Hey guys. Sorry for the late one. Been away up till now. I didn't exactly fix or solve the problem. I just found a way around it. Created a new profile. Copied everything off the old profile to the new profile folder. Then somehow it would like a charm.