Thunderbird has become a pain now for a number of months- regardless of any updates. On first start up if I click on anything on Thunderbird before ALL email accounts have completely finished downloading, Thunderbird locks up and displays not responding on the top of the screen. I have to wait ten minutes and longer before I can start reading a email until every email on every email account has finished downloading. When a site says it is sending a verification email - before I can see that email when I start Thunderbird - the verification email needs to be resent because it has run out of time. This never happened a year ago - now it is daily! I don't know what Mozilla is doing to Thunderbird but it is now highly unreliable! If it was not the only free email client software I would have dumped it by now. Why is it doing this?