TB (Thunderbird) lost its ability to connect to the server, for downloading messages. I don't know why this happened, and I can't figure out how to fix it. I have 2 email accounts in use, in my W10 (Windows 10) TB setup. These are 2 different names @ charter.net. This setup had been working flawlessly for a long time; maybe, a year - and suddenly it couldn't connect to the server for retrieving emails. I have a 2nd OS (operating system) on my computer, antiX 21 (a21) Linux. That OS also has an installation of TB, and it's working perfectly. The problems are confined to the W10 setup. I've been going through the TB settings repeatedly, over & over. The only thing I see out of whack, is in the box showing the imap lines & passwords. (Tools/Settings/Privacy & Security/Saved passwords) I used the a21 setup for comparison... In the W10 setup, there is now only one line, instead of 4; an imap line for the default account. The imap line for the other account is gone. Both of the smtp lines are gone. I don't see any way to replace those 3 missing lines of data, in that passwords data box. I tried closing it down, restarting it, and entering the passwords with the checkmark checked for saving the password. The most I was able to accomplish was switching things around, and increasing to having 2 lines in the box. Now, it shows the imap line for the 2nd account, followed by the smtp line for the 1st account. I've hit a point where I'm considering trying to delete the accounts entirely in TB, to start them over from scratch. That, or deleting the installation entirely, to start TB over from scratch. Why can't the server data & passwords be edited? How can I fix this, to make TB work again?