Just an FYI,

    I can send from Outlook but not Thunderbird. Also Thunderbird did work for a couple weeks and then quit.

try restarting you computer in safe mode with networking My guess is Thunderbird is being blocked by your anti virus firewall. If it works in safe mode then it will be almost certain.

Hi Matt,

    Thanks for the reply. I turned off the firewall in the antivirus software and tried to resend the message. The send still failed immediately. From past experience with the product I do know that if the firewall is causing an issue, turning it off does solve it. So where do we go from here?

Anti virus has a three pronged way to mess up.

! use it's firewall. 2. Try and scan outgoing mail and make a total mess of that to the point it does not go. 3. Try and scan incoming mail and make a mess of that.

Additionally there are on access scans that cause havoc for some. Script timeouts in Thunderbird are most common manifestation. But incomplete indexes, disappearing mail lists are also the result of anti virus activity.

And of course the grand daddy of them all. The anti virus simply quarantines your entire inbox file to kill a mosquito.

So from experience with anti virus programs simply using safe mode is the number one diagnostic method for all of those things. Safe mode also prevents all sorts of other "on startup" processes. Most of which are either useless or a potential problem. Time spent with MSCONFIG on most machines startup items will pay dividends of speed on almost all machines

You get a time out immediately still sounds like a third party application to me. It might even be one of the ancient comcast modems that block comcasts mail server ports. Given how cagy you have been with troubleshooting information it is difficult to do more that guess.