When you run Outlook 2003 in Cached Exchange Mode, all the Outlook clients in the Exchange Server 2003 organization try to download the offline address book at the same time

When you run Microsoft Office Outlook 2003 in Cached Exchange Mode, a period of very high network usage occurs. This high network usage occurs because all the Outlook clients in the Microsoft Exchange Server 2003 organization try to download the whole offline address book at the same time.

Additionally, when you click the arrow next to the Send/Receive Status icon in the Outlook status bar and then click Details, the status bar displays a message that is similar to the following: Additionally, several events that have event ID 27 may be logged in the Application log. These events occur if the following conditions are true:

• You are running Microsoft Office Outlook 2003 Service Pack 1 (SP1).
• You have the Offline Address Book logging feature enabled.

Note By default, the Offline Address Book logging feature is enabled in Outlook 2003.

These events are similar to the following:

Event Source : Outlook
Event ID : 27
Event Type : Error
Description : OAB ModDif failed. (Details record in event data).

Event Source : Outlook
Event ID : 27
Event Type : Information
Description : Starting OAB Download.

Event Source : Outlook
Event ID : 27
Event Type : Information
Description : OAB Download Succeeded.

This problem occurs during the offline address book generation process. If an address that is entered in the offline address book contains an SMTP proxy address that is longer than 64 characters, the Outlook client does not apply the .diff file. The Outlook client then downloads the whole offline address book.

Note The 64-character limit includes everything to the left up to and including the at sign (@). The domain name is not included.

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 this specific problem. 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.

Prerequisites

You must install Microsoft Exchange Server 2003 Service Pack 1 (SP1) before you apply the hotfix.
For more information, click the following article number to view the article in the Microsoft Knowledge Base:

Restart requirement

You do not have to restart the computer after you apply the 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.

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

For more information, click the following article number to view the article in the Microsoft Knowledge Base: For more information, click the following article number to view the article in the Microsoft Knowledge Base: