Since you have Authentication method for gmail set to Normal Password you need Less Secure Apps turned on at gmail. Either that or change it from Normal Password to Oauth2.

Thanks for your reply Airmail Actually I did have it set on Oauth2. You gave me the idea to try changing it to Normal Password and did and changed my Gmail account to Less Secure. In any case, I still get the timed out error message when I try to Send.

Your posted screen shot clearly shows Normal Password and not oauth2. Are you sure you are working on the SMTP settings and not the incoming IMAP settings.

Normal password is OK, but you should use STARTTLS security on port 587 (or SSL/TLS on port 465).

http://kb.mozillazine.org/Using_Gmail_with_Thunderbird_and_Mozilla_Suite

If you still get timeout errors, run in Windows safe mode to check the possibility your antivirus is causing the problem (it's not sufficient to 'turn off' AV in normal mode).

For W10, Shift+Restart, Troubleshooting, Advanced options, Startup Settings, Restart, 5.

Yes Airmail you are correct. My error. I thought I had included both instances of STMP settings.

Thank you sfhowes for your reply. Following your direction:

1. I did change to use ssl/tls which automatically changed the port to 465. It's set to Normal password. Same problem.
2. Going into SafeMode option 5, I checked all options to make sure the above was still set. Then tried to send. Google queried for password. Error message "Go to support/ etc/ answer/78754 (failure)" which I googled and chose the option for Tbird. I had to sign in to Google for my account using the same password and was able to sign in online.
3. I then went to see what security setting was enabled. The Less Secure option had been turned off. I turned it on.
4. Then going back to Tbird, I had to give passwords for both IMAP and then SMTP.
5. I set a test message AND IT WORKED! I closed down Tbird and reopened it, sending another test message, which also worked. Closing TB, I rebooted the computer normally.
6. Opening TB, once again was asked for Gmail/IMAP and then Gmail/SMTP passwords, checking the remember this box in both cases.

# I sent a test message, AND AGAIN IT WORKED with a message from my Gmail account.  
# I then sent a message from an alternative non-Gmail account, again it was sent and received.

So I am back in business again although I don't understand how/why the Less Secure setting at Gmail was turned off. I will go there if I have problems in the future.

I want to Thank You sfhowes and airmail for your time, knowledge, and efforts on this for me. I'd like to buy you both a beer wherever you are, but I wouldn't know how to proceed. If you have significant others, have them give you a Hug for me as a consolation. G-