You need to supply some basic info when asking question so people know what you are talking about. # what OS? # What version of Thunderbird? # what anti-virus/firewall product do you use? then Please supply info: In Thunderbird: * Help > Troubleshooting information * click on 'copy text to clipboard' * paste the info in this forum. * You can edit all info on fonts and printers, but nothing else. re : ''When I open the program it works but sometime later it stops after getting new messages.'' So, thunderbird launches fine and looks for and downloads new messages, but 'stops' after getting new messages. What do you mean by 'stops'? Stops looking for new messages? Stops downloading the new messages? Seems to have a 'Not Responding' message at the top? Just freezes and is not reponding to anything? The above issue does not sound the same as this one : ''It opens but does not work and there is warning box open which will not close.'' Here you say, it opens ok, but it fails to connect to server, fails to find messages and fails to download, all you get is a warning box that cannot be closed. So do both of these situation occur when you launch Thunderbird? where you either get the first situation or the second, but it happens all the time. What 'warning box' are you talking about? What does it say Word for word ? It would be better if you posted an image showing that warning box. What happens when you start Thunderbird in safe mode? * https://support.mozilla.org/en-US/kb/safe-mode-thunderbird#w_how-to-start-thunderbird-in-safe-mode Does it work ok in Thunderbirds Safe Mode?