Hi,
Mysql on my server crash once a day

I don't know what happen. After reboot the Mysql then it ok for a day then crash again. I look into the event log and see that same error message everytime. Does anyone have this problem or know how to fix. Thanks a lot in advances.
Error Logs
Faulting application mysqld-nt.exe, version 0.0.0.0, faulting module mysqld-nt.exe, version 0.0.0.0, fault address 0x001e6eb0.
For more information, see Help and Support Center at
http://go.microsoft.com/fwlink/events.asp.
and then follow another Error
System.Web.HttpException: Could not access 'CDO.Message' object. ---> System.Reflection.TargetInvocationException: Exception has been thrown by the target of an invocation. ---> System.Runtime.InteropServices.COMException (0x8004020F): The server rejected one or more recipient addresses. The server response was: 550 <oidw@yahoo.com>, Recipient unknown