OS X Yosemite 10.10.3 Mail keep quitting unexpectedly. This started happening after the last update I'm just wondering that why Mail keeps quitting after the 10.10.3 update.
The mail app worked fine and I never had to quit it, but now it happens occasionally.

Sorry I didn't provide those informations.
Here is the User Diagnostic Reports:

Crashed Thread:        18  Dispatch queue: NSOperationQueue 0x7fbff45644a0 :: NSOperation 0x7fbff7e23ee0 (QOS: UTILITY)
Exception Type:        EXC_CRASH (SIGABRT)
Thread 18 Crashed:: Dispatch queue: NSOperationQueue 0x7fbff45644a0 :: NSOperation 0x7fbff7e23ee0 (QOS: UTILITY)
Thread 18 crashed with X86 Thread State (64-bit):
    0x7fff8d4d9000 -     0x7fff8d4e4ff7  com.apple.CrashReporterSupport (10.10 - 631) &lt;D87A64FA-64B1-3B23-BB43-ADE173C108C6&gt; /System/Library/PrivateFrameworks/CrashReporterSupport.framework/Versions/A/CrashReporterSupport


Let me know if I can provide more info to solve my question.

What I actually want to do is to make the mail app stable instead of crashing 2 or 3 times a day.
I found the source of those repetitive crashes : a rule that tried moving email in a directory that does not exist anymore. Under 10.10.2 Mail would simply not do anything. Under 10.10.3 Mail 8.2 crashed and corrupt the mail index. Simply fixing the rules did solve my problem.