Inbound SMTP Session Hangs Waiting for CRLF.CRLF Which Was Already Received (306557)


The information in this article applies to:

  • Microsoft Windows 2000 Server SP1
  • Microsoft Windows 2000 Server SP2
  • Microsoft Windows 2000 Advanced Server SP1
  • Microsoft Windows 2000 Advanced Server SP2
  • Microsoft Windows 2000 Professional SP1
  • Microsoft Windows 2000 Professional SP2
  • Microsoft Exchange 2000 Server
This article was previously published under Q306557

SYMPTOMS

When specifically-formatted messages are received by the SMTP service, the messages may not be properly processed. Instead, the SMTP service may stop responding (hang) after the message has been received and the message is not sent to its destination.

CAUSE

This problem is caused by the Windows 2000 Server SMTP service failing to properly detect the termination of an SMTP message. When the SMTP service is given specifically formatted messages that are the exact length of an internal SMTP memory buffer, the SMTP service does not properly detect the CRLF.CRLF value that denotes the termination of the SMTP message. Because of this, the SMTP service continues to wait for the message termination indicator it has already received.

RESOLUTION

To resolve this problem, obtain the latest service pack for Windows 2000. For additional information, click the following article number to view the article in the Microsoft Knowledge Base:

260910 How to Obtain the Latest Windows 2000 Service Pack

The English version of this fix should have the following file attributes or later:
   Date         Time   Version        Size     File name
   -------------------------------------------------------
   28-Feb-2002  18:08  5.0.2195.4624  321,296  Aqueue.dll
   28-Feb-2002  18:08  5.0.2195.4624   66,832  Mailmsg.dll
   28-Feb-2002  18:08  5.0.2195.4624   38,160  Ntfsdrv.dll
   28-Feb-2002  18:08  5.0.2195.4981  438,544  Smtpsvc.dll

STATUS

Microsoft has confirmed that this is a problem in the Microsoft products that are listed at the beginning of this article. This problem was first corrected in Windows 2000 Service Pack 3.

MORE INFORMATION

For additional information about how to obtain a hotfix for Windows 2000 Datacenter Server, click the article number below to view the article in the Microsoft Knowledge Base:

265173 The Datacenter Program and Windows 2000 Datacenter Server Product

For additional information about how to install multiple hotfixes with only one reboot, click the article number below to view the article in the Microsoft Knowledge Base:

296861 Use QChain.exe to Install Multiple Hotfixes with One Reboot

Modification Type:MinorLast Reviewed:9/26/2005
Keywords:kbHotfixServer kbQFE kbbug kbenv kbfix kbSysAdmin kbWin2000PreSP3Fix kbWin2000sp3fix KB306557
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