Event ID 2019 occurs when nonpaged pool (NPP) memory is exhausted on a computer that is running Exchange Server 2003


On a computer that is running Exchange Server 2003, nonpaged pool (NPP) memory is exhausted.Then, the server crashes and you have to restart the server to resume services. When this problem occurs, you see the following symptoms:
  • The
    Netstat command shows several POP3 sessions in a CLOSE_WAIT state.
  • New POP3 clients cannot connect to the Exchange server.
  • Handle count for the Inetinfo.exe process increases significantly.
  • A nonpaged pool error is generated in the System log that resembles the following message:
    Event Type: Error Event Source: Srv Event Category: None Event ID: 2019 Description: The server was unable to allocate from the system nonpaged pool because the pool was empty.


This issue occurs when a critical section deadlock occurs in the Inetinfo.exe process for POP3 connections because the corresponding system resources are not released.


Hotfix information

A supported hotfix is available from Microsoft. However, this hotfix is intended to correct only the problem that is described in this article. Apply this hotfix only to systems that are experiencing the problem described in this article. This hotfix might receive additional testing. Therefore, if you are not severely affected by this problem, we recommend that you wait for the next software update that contains this hotfix.

If the hotfix is available for download, there is a "Hotfix download available" section at the top of this Knowledge Base article. If this section does not appear, contact Microsoft Customer Service and Support to obtain the hotfix.

Note If additional issues occur or if any troubleshooting is required, you might have to create a separate service request. The usual support costs will apply to additional support questions and issues that do not qualify for this specific hotfix. For a complete list of Microsoft Customer Service and Support telephone numbers or to create a separate service request, visit the following Microsoft Web site: Note The "Hotfix download available" form displays the languages for which the hotfix is available. If you do not see your language, it is because a hotfix is not available for that language.


Because of file dependencies, this hotfix requires Microsoft Exchange Server 2003 Service Pack 2 to be installed on the server.

For more information, click the following article number to view the article in the Microsoft Knowledge Base:
836993 How to obtain the latest service packs for Exchange Server 2003

Restart requirement

You do not have to restart the computer after you apply this hotfix. However, the Internet Information Services (IIS) Admin Service and all dependent services are restarted automatically when you apply this hotfix.

Hotfix replacement information

This hotfix does not replace any other hotfixes.

File information

The English version of this hotfix has the file attributes (or later file attributes) that are listed in the following table. The dates and times for these files are listed in Coordinated Universal Time (UTC). When you view the file information, it is converted to local time. To find the difference between UTC and local time, use the Time Zone tab in the Date and Time tool in Control Panel.
File nameFile versionFile sizeDateTime


Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.

Article ID: 968684 - Last Review: Feb 16, 2017 - Revision: 3