MSExchangePOP3 service crashes in an Exchange Server 2007 environment

When a client issues a QUIT command to end a POP3 session, the MSExchangePOP3 service crashes occasionally on a Microsoft Exchange Server 2007 Client Access server. Additionally, the following event is logged in the Application log:
Log Name: Application
Source: Application Error
Date: Date
Event ID: 1000
Task Category: (100)
Level: Error
Keywords: Classic
User: N/A
Computer: Computer
Faulting application name: Microsoft.Exchange.Pop3.exe, version: version, time stamp: time stamp
Faulting module name: unknown, version:, time stamp: 0x00000000
Exception code: 0xc0000005
Fault offset: offset
Faulting process id: process id
Faulting application start time: start time
Faulting application path: C:\Program Files\Microsoft\Exchange Server\ClientAccess\PopImap\Microsoft.Exchange.Pop3.exe
Faulting module path: unknown
Report Id: report id
This issue occurs because of a NullReferenceException exception when the Exchange server processes a POP3 session quit command. The NullReferenceException exception is caused by a race condition during the POP3 session object disposal. In this race condition, the VirtualServer object is set to NULL before it is used. Therefore, the MSExchangePOP3 service crashes.
To resolve this issue, install the following update rollup:
2655203 Description of Update Rollup 7 for Exchange Server 2007 Service Pack 3
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.
For more information about the QUIT command, visit the following Microsoft website:

Article ID: 2677979 - Last Review: 04/16/2012 16:44:00 - Revision: 1.0

Microsoft Exchange Server 2007 Service Pack 3

  • kbqfe kbfix kbsurveynew kbexpertiseinter KB2677979