I have been using thunderbird on my mac for over a year and have numerous IMAP and POP 3 account associated with the account. Suddenly today every time I open Thunderbird after 5 seconds it comes up application not responding. I have done the following but it is still not working. -Completely deleted Thunderbird from my Mac and then imported a back up profile - this still does exactly the same on startup. -In the 5 seconds I have before it goes to "application not responding" I have changed the settings of check mail every 1 min to every 15 min. Of course eveytime I open it there is more emails it is trying to receive. This is causing so much havoc for me and is rendering me useless at work. Please can someone help!