Localhost, or IP 127.0.0.1 is your network adapters loopback address. The only software that as a matter of course uses it (Other than Thunderbird in debug mode) are anti virus programs and their insidious proxies to scan mail. Restart the operating system in '''[http://en.wikipedia.org/wiki/Safe_mode 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: [https://support.microsoft.com/en-us/help/12376/windows-10-start-your-pc-in-safe-mode Windows 10], [http://windows.microsoft.com/en-us/windows-8/windows-startup-settings-safe-mode Windows 8], [http://windows.microsoft.com/en-us/windows/start-computer-safe-mode#start-computer-safe-mode=windows-7 Windows 7], [http://windows.microsoft.com/en-us/windows/start-computer-safe-mode#start-computer-safe-mode=windows-vista Windows Vista], [http://www.microsoft.com/resources/documentation/windows/xp/all/proddocs/en-us/boot_failsafe.mspx?mfr=true" Windows XP], [http://support.apple.com/kb/ht1564 OSX] If things work in that mode I would guess that your anti virus is lying to you about being stopped. Or it stopped and did not remove it's outgoing block of using the loopback address.

Thanks for answering, but safe mode didn't work for the one account again.
 Can I bypass or change the localhost  connection?

Hi Matt- Thanks for answering, but safe mode didn't work for the one account again. Can I bypass or change the localhost connection? Bob

I would suggest you try disabling the email scanning in your anti virus product. hopefully that will bypass the use of localhost.

I also tried to disable the anti-virus and that didn't help either.