Outlook 2003 stops responding when you try to plan a meeting that contains users who are behind a firewall

You connect to a Microsoft Exchange Server computer and then try to plan a meeting in Microsoft Office Outlook 2003. Outlook 2003 may appear to stop responding (hang) if the following conditions are true.

• The planner options are turned on to display the details of the meeting attendees.
• The meeting that you are trying to plan contains attendees whose mailboxes are homed on an Exchange Server computer that is behind a firewall.

This problem occurs because Outlook 2003 cannot connect to the attendee mailboxes that are homed on an Exchange Server computer that is behind a firewall.

When Calendar planner options are enabled, Outlook tries to retrieve Calendar details for the attendees. To do this, Outlook must log on to the attendees' mailboxes. If the attendees' Exchange Server computer is behind a firewall, the Exchange Server computer refuses RPC requests. It may take some time for Outlook to determine that the Exchange Server computer is not available. During this time, Outlook appears to stop responding.

This problem was first fixed in a hotfix that is now contained in a service pack. If you installed the latest Office 2003 service pack, you do not have to install the hotfix.

Service pack information

This problem is corrected in Office 2003 Service Pack 2.

To resolve this problem, obtain the latest service pack for Office 2003. For more information, click the following article number to view the article in the Microsoft Knowledge Base:

After you install the service pack, follow the steps that are listed in the "More Information" section of the article to set the IgnoreServerConnection registry key and to activate the hotfix.

Hotfix information

How to obtain the hotfix

This issue is fixed in the Outlook 2003 Hotfix Package that is dated May 20, 2004. For additional information, click the following article number to view the article in the Microsoft Knowledge Base: After you install this hotfix, follow the steps that are listed in the "More Information" section of this article to set the IgnoreServerConnection registry key and to activate the hotfix.

Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section. This problem was first corrected in Office 2003 Service Pack 2.

Warning If you use Registry Editor incorrectly, you may cause serious problems that may require you to reinstall your operating system. Microsoft cannot guarantee that you can solve problems that result from using Registry Editor incorrectly. Use Registry Editor at your own risk.
To activate this hotfix, follow these steps:

1. Quit Outlook 2003.
2. Click Start, and then click Run.
3. In the Open box, type regedit, and then click OK.
4. Locate, and then click to select the following registry subkey:
   HKEY_CURRENT_USER\Software\Microsoft\Office\11.0\Outlook\Preferences
5. After you select the subkey that is specified in step 4, point to New on the Edit menu, and then click String Value.
6. Type IgnoreServerConnection, and then press ENTER.
7. Right-click IgnoreServerConnection, and then click Modify.
8. In the Value data box, type the server name(s) delimited with a semicolon and no spaces such as server1;server2;server3, and then click OK.
9. On the File menu, click Exit to quit Registry Editor.