I finally enabled Thunderbird to work with Gmail Enhanced Security. I enabled two-step verification on my Gmail account.

One has to enable two-step verification, and establish an application specific password that you substitute for the regular Gmail password that you inserted in your email client.

I found the link below helpful in resetting Thunderbird. Now it works like a charm.

http://www.slipstick.com/outlook/email/outlook-synchronize-subscribed-fo...

I am not a developer or programmer, so I do not know if those of you who continually work on Thunderbird plan on enhancing its security to work with Google but I found the above to be a workaround, if this helps anyone for now.

Two stepverification:

If you are using a computer and a phone to access emails then you need to set up the 2 step verification. You need to create an application specific password for Thunderbird that you use instead of the normal password.

If you are only using gmail via your computer then it is not required. Info:

• http://kb.mozillazine.org/Gmail

section: Two step verification

The Google Account help advocates using two step authentication. That sends a code (a minimum of once a month but ideally every time you log in) to your cell phone that you need to enter when logging in using a browser. However applications such as email clients can't do that. If you configure two step verification you need to create an application specific password for Thunderbird that you use instead of the normal password. The application specific password doesn't change when a new code is sent to your cell phone.

Two step verification is not needed, and not recommended. Use a strong password, and don't use the same password with other email providers/web sites, instead. However, if you have another email account it is a good idea to set a recovery email address in case you ever forget/lose your password.

More info on setting up 2 step verification:

• https://support.google.com/mail/answer/1173270?hl=en

2 step verification is a means of making it more secure to access gmail using a browser and a phone.

When this enhanced feature was enabled in my Gmail account, Thunderbird would no longer function.

The option presented is to leave it disabled, and Thunderbird would function as always.

To leave it enabled, one turns on 2-step, and then obtains an application specific password. Regarding the verification codes, for my situation, they are not needed as I have Google register my Desktop PC, and chose application specific passwords for Thunderbird, and my Smartphone.

Now everything functions as before.