Ever since upgrading to Mavericks Mail hasnt worked for me at all. The light comes on under the app but it immediately goes to not responding. Maybe if I leave it for a few hours itll work, Im not sure. I believe this problem stems from the way Internet Accounts are now handled within Mavericks. This thought comes from the fact that when I go into accounts in System Prefs the window hangs for ages before eventually bringing me in with most of my accounts missing and only iCloud stating its hooked up to Mail. I can add new accounts but it will crash if I try to sync Mail with them. What I want to try, unless someone has a better idea, is cleaning out all my accounts and re-doing them. Problem is I dont want to use System Prefs since it keeps crashing. Could it just be a preference file to trash or something maybe? For now Im going to try using Thunderbird for my emails. I dont like it as much but apple completely broke their mail app for me so until they patch it or I can get some news on how to get it working I need an alternative.