inbox is unavailable???
Unable to open the folder Inbox on best.one@comcast.net because it is in use by some other operation. Please wait for that operation to finish and then select the folder again.
Alle svar (1)
Sounds like you have Anti-Virus which is scanning files in Thunderbird. It's all too common that AV products scan anything gets opened and it can cause non responsive type issues.
What Anti-Virus do you use ?
Please make sure any AV or malware product cannot scan any Thunderbird profile folder. You may need to set up an Exception.