Cannot receive or send eMails - getting Thunderbird Error Code (iMAP): 1014

I have just started having this problem. I'm using Windows 7 Pro and Thunderbird as my eMail APP. Haven't had problems recently but today I cannot log in unless it is on the Web Site and using a NEW Password. I keep getting the Thunderbird Error Code (iMAP): 1014, however, nothing has changed in the way of settings from yesterday when I was logging in just fine.

Any suggestions to WHY a protected comcast.net system and home computer system could be garbled up like this overnight? All of my Thunderbird settings look O.K., and I downloaded and installed a NEW package, SAME VERSION, and still have the problem.

HELP,   PLEASE!!!