I am having a problem with my email program, Thunderbird. Up until 2 days ago, this has been working flawlessly for years, until it suddenly stopped sending or receiving emails. My initial thought was that a setting had been corrupted somewhere, but I checked everything (IMAP, SMTP settings etc.). I contacted my ISP, and confirmed with them that my settings were correct, username and password (I can still log into my web mail just fine) etc. Everything is as it should be. I have tried uninstalling Thunderbird using apt remove, and opted to install the Snap version instead, but still, Thunderbird absolutely refuses to communicate in any way. I have noticed that even if I go into Thunderbird Help, and click on one of the links there, they are instantly blocked too!
As a sanity check, I also have another laptop running Linux Mint. I installed my profile on Thunderbird on that machine, and in a matter of minutes I had my email running (exact same user credentials, ISP, home network, email account). I am therefore thinking that this has got to be an OS problem on my desktop. This is no longer looking like a Thunderbird/Profile/ISP/Network issue.
How and why is Thunderbird (version 91.5.1 64bit) suddenly blocked from the Internet on my Ubuntu 20.04.3 LTS (x86-64) based desktop? Is there a firewall issue I am not aware of perhaps?
Thanks guys.
UpdateI just tried again, and this is still not working! See the screenshot, where I have attempted to use the auto-config option when setting up a new account in Thunderbird. The exact same process works without a problem on my laptop on the same network, and the laptop is running Linux Mint...
Thunderbird email fails to connect to server under Ubuntu
Thunderbird correctly detects settings from mail server under Linux Mint
3 Answers
Switch from Start-TLS to TLS worked for me...
1Well, I thought I had fixed this, but no. What I did was uninstall Thunderbird (apt-get remove) and then install it using the SNAP version. After this I discovered that my VPN was getting in the way, and with it disabled I had working email again. Thought I had solved my problem, except now that bloody Thunderbird has no credible means of restoring an old profile, all my emails were "lost". Today I attempted to restore my original version (apt-get install thunderbird) and voila, my emails and profile are all back, but I am back to square one again, being unable to send or receive new emails!
Basically, (today) when I attempt to setup a new account (although my old profile account should work jut fine, as nothing has changed) I get this:
Regardless of whether I try to get the certificate or "confirm Security Exception" I end up with this:
The Snap install at least proved one thing. There is nothing wrong with my installation of Thunderbird/credentials/network etc. etc. as this was working (I could download and send emails no problem via Snap version of Thunderbird) but as soon as I go back to the original method of install (but exactly the same version of Thunderbird) that has worked for years (even with a complete reinstall) Ubuntu is simply blocking it from working! This is truly frustrating and been going on for weeks now!
What if your initial suspicion was correct? Sudo apt remove would remove the binary, but leave the config files. Since it worked fine on another device, one might reasonably assume a corrupted config file, as those were not recreated, but re-used.
Sudo apt purge will do everything "remove" does, but also irrecoverably remove all config files.
