deactivate one of the e-mail servers, but keeping the old messages
I use Thunderbird to collect e-mails from several e-mail providers. Recently, one of the e-mail servers, which I used for at least eight years, was discontinued. I could switch off automatic e-mail check for this account, however pressing "Get All New Messages" makes Thunderbird attempting to connect to the server and as a result fails, making at least two error notification windows to pop up. Is it possible to completely deactivate one of the servers, but keep the rest the way it was before.
Wšykne wótegrona (1)
If you don't mind moving the folders for that account to your Local Folders, you could simply remove the account: https://support.mozilla.org/en-US/questions/1026691 Bear in mind that if you do that the messages aren't backed up on a server any more, so you need to make regular backup copies of your Thunderbird profile if you want to keep them safe.