When I want to delete an open email I have always used the delete function in the upper right hand corner of the open email. Since the program did it's major update there are times when I click on delete nothing happens and I have to keep clicking on it several times for it to finally delete the email. Also, when I open Thunderbird and then try to download my messages, many times the screen goes gray and I get a message at the top of the page that says Thunderbird is not responding. I have disabled all add ons and have tried to resolve this in troubleshooting mode but still no resolution. Thunderbird just isn't the same since the major update.