There are several other approaches you can try for handling Mail crashes. The first is to use OnyX or another system maintenance program to clear the system and application caches, and also the Mail Downloads folder (which can also be done by hand at the /username/Library/Mail Downloads/ folder). In addition, removing the Mail preferences file is another common approach, which is called "com.apple.Mail.plist" and is located in the /username/Library/Preferences/ folder. Doing this will require you to set up your accounts again, but your emails and inbox organization should still be intact once the accounts are set up. Lastly, if Mail crashes on launch, you can try launching it in "Safe" mode (where it does not immediately check for new messages or display any downloaded emails) by holding the shift key while it launches. This will allow you to change any faulty settings or rebuild mailboxes as may be required to fix the problem.