Problem with thunderbird in ububuntu 17.04.

[Kyle]

It doesn't sound like your problem is with Thunderbird. I think Gmail is 
the culprit here. It's possible it doesn't fully recognize you and 
thinks you're trying to login from an unknown device. You will need to 
verify that you are you by other means before Google will unblock your 
access to that account. It's possible that logging into the blocked 
account via gmail.com will fix this, but you also may need to authorize 
Thunderbird to access your Google account, which it usually does 
automatically via a popup with an allow button. Otherwise, there are a 
few other options you can try that may also unblock your access.
Sent from the here and now