Thunderbird shows email messages from the wrong account; Sending email "Request failed: Mailbox unavailable"
Thunderbird shows email messages from the wrong account. The messages show properly in Yahoo website and on other computers using Thunderbird. Concurrent with this new issue, I now get message: Sending of the message failed. An error occurred while sending mail. The mail server responded: "Request failed: Mailbox unavailable. Please verify that your email address is correct in your account settings and try again."
I have verified the settings. Searching for help with Thunderbird, I see references to index files getting corrupt. However, I struggle with the correction procedures. When I right click on the bolded email address, "Properties" is not an option on the drop down menu. I cannot find a "Fix folders" button.
BTW, I did contribute December 17, 2025, it seems like a pretty good way to say "thank you!" Jim