ok, on of the difficulties in setting up an outgoing server is your anti virus. They often get involved in the process thinking that the setup is mail and try and scan it. The rest is not pretty and very much what you are describing.

SO a fairly standard approach is reboot into the operating system safe mode with Networking. This loads only the very basics needed to start your computer while enabling an Internet connection. Click on your operating system for instructions on how to start in safe mode: [http://windows.microsoft.com/en-us/windows/start-computer-safe-mode#start-computer-safe-mode=windows-7 Windows 7

While in safe mode attempt to set up the smtp server and /or use it if you already have it set up.

If you are using Verizons security suite please read up on McAfee here. IT has a poor long term relationship with Thunderbird.

Matt,

Thanks for the suggestions. I use Comodo for everything, and it has been very well behaved in the past. I've had to clean out too many viruses from machines supposedly "protected" by McAfee products.

Restarting in Safe Mode produced exactly the same result after running the "Add new eMail" setup wizard -- "Password or User name is invalid", same as when the firewall / antivirus was active. No joy on outgoing connections.

Any other ideas?

Thanks,

Dave

Do you use a proxy to connect to the internet?

Matt,

No proxy.

Thanks,,

Dave