Must run, then pause VPN to get or send email w/Thunderbird
I am using Thunderbird 102.4.2 and Windows 11, 21H2 build 22000,1219. I've used TB at least 10 years and have never had an issue getting or sending email until the past few months. Beginning with an bug fix/update to Win 11 several months ago I can no longer send nor receive email (smtp and pop3) unless I first start, then pause my Nord VPN. If VPN has not been started, or if it is running, when I try to send mail, I eventually get a msg:
"Sending of the message failed. An error occurred while sending mail: Outgoing server (SMTP) error. The server responded: Cannot connect to SMTP server 207.115.64.67 (207.115.64.67:587), connect error 10060."
If I pause the VPN, the mail goes right out. Attempting to get my email gives similar results.
After extensive testing, this seems to be Window 11 caused. Two weeks ago, I fired up a computer that had not been turned on for six months -- it's located at a different house. I would not allow Windows to update on that computer but, in a controlled fashion, updated TB and Nord while verifying TB ability to get and send email with no VPN, VPN running, and VPN paused. TB worked perfectly.
After 4 or 5 days, I allowed Win 11 to update. Instantly, this computer began to act like my other one -- only way to get or send email is with VPN running, but paused. This indicates to me that it is a Win 11 caused problem. However, I know that Microsoft does the least that it can to work with other companies so I am asking: 1) Anyone else having this issue; and, 2) Does TB have a fix?
All other Internet connections continue to work, on both machines, as before. i.e. zero problems with browsers, app, or anything else.
All Replies (2)
Hello
I don't have this issue (I don't use Windows) and it's very probably not possible to fix this at the Thunderbird level, because this is suggesting that the Windows update has changed something in the software firewall (probably Windows Defender) and that when the VPN is active, the change is reverted - it's quite possible that a VPN will fiddle with Firewall.
Setting a log in the Windows Firewall is possible but rather involved. A cruder method is to change the Windows Firewall to set a rule allowing explicitly output to the port 587 and see what happens. But it's still involved for someone not used to computers. And it's not easy to help users remotely unless one has exactly the same OS version - I don't have at the moment access to any computer with Windows 11 so I can't check how it's done currently. I can try if you are willing, another possibility is to get the help of a more computer oriented person if necessary.
BTW your other applications use probably all the port 443 to connect to servers and it's not likely that any system change will hinder this kind of access - it would break too many things.
Thanks for the port suggestion. I'll play around with that.