error msg upon startup: sending of msg failed.
Sometimes upon start up Thunderbird gives "sending of message failed". I wasn't sending a message, Thunderbird just started. Today, there were several message boxes, "sending of message failed".
Running version 52.9.1 32 bit version on Windows 7. This problem has persisted through several updates.
Alla svar (3)
Update:
And, it turns out, my Thunderbird sent an old email to my assistant's email address upon start up, without being told.
I suggest you open the "outbox" folder and delete the pending mail.
I don't use my outbox or the other local folders. POP account to the email account hosted by the web hosting company I use.
I did compact and repair all of the local folders, in case that might help.