The Exchange Server version 5.5 Service Pack 3 message transfer agent (MTA) may stop unexpectedly with a call stack that is similar to the following when the MTA attempts to gain access to a particular object in the MTA database:
FramePtr  RetAddr   Param1   Param2   Param3   Function Name
068afb30  004f56d3  08293ae0 00000003 034b8a5a EMSMTA!snpuputn+0x4e
068aff28  004ea2f9  00554b13 00694aa8 034e8508 EMSMTA!otpmrfo+0x923
068aff48  004ea186  00554b13 0884cf90 000041e8 EMSMTA!otpmmai2+0x129
068aff8c  00554b98  000041e8 034e4305 00000013 EMSMTA!otpmmain+0x3c6
068affb8  77f04ee8  00000013 000041e8 034e4305 EMSMTA!sbpiwbep+0x58
068affec  00000000  00000000 00000000 00000000 KERNEL32!BaseThreadStart+0x51
					
The MTA may log several events that are similar to the following before the MTA stops unexpectedly:
Event ID: 2182
An MTA database server error was encountered while copying an object. Called from MTA. Procedure 124. Database error code: ODXFATAL - Internal or Application Error. Object at fault: 060008AC. [DB Server DISP:FANOUT 19 269] (14) 
Event ID: 9405
An unexpected error has occurred which may cause the MTA to terminate.  Error: Access violation (0xc0000005) at Address 0x436fde reading from 0x31206. [BASE DISP:FANOUT 19] (16) 
Event ID: 9405
An unexpected error has occurred which may cause the MTA to terminate.  Error: Releasing unowned write lock 5589790. [BASE DISP:ROUTER 30] (16)
In this particular case, the MTA stops while it attempts to gain access to object 060008AC or db0008ac.dat, which the MTA referenced in the event ID 2182 error message.