The latest version of Tbird refuses to send mail.
I have been using Thunderbird for several years. About 4 days ago I upgraded to the latest version. Now I am unable to send mail. I am using imap.comcast.net as the incoming server and smtp.comcast.net as the outgoing server. I can receive mail with no problem but cannot send to anyone using jim_robinson@comcast.net as my email address. I have no other account set up in Thunderbird.