Mail Quits unexpectedly every time it opens
I had similar problem. The crash report was:

Exception Type:        EXC_CRASH (SIGABRT)
Exception Codes:       0x0000000000000000, 0x0000000000000000
Exception Note:        EXC_CORPSE_NOTIFY 


If your crash note is  EXC_CORPSE_NOTIFY, Then deleting all your accounts and re-adding them will solve your problem.