Outlook Web Access stops responding when you try to access a mailbox on an Exchange 5.5 computer

When you use Microsoft Outlook Web Access (OWA) to access a mailbox on a computer that is running Microsoft Exchange Server 5.5, OWA may stop responding.

Additionally, when you use a third-party program that uses Collaborative Data Objects (CDO) to access a mailbox on a computer that is running Exchange 5.5, the third-party program may stop responding.

When the third-party program stops responding, the following event may be logged on the mailbox server that is being accessed through OWA:

Source: MSExchangeISPriv
Event ID: 2078
Description: Unable to submit, send, or transfer out a message. Check PR_Recipient_Number, PR_Recipient_Type, PR_Report_Type

This problem occurs when you try to access a user account that was previously accessed by a client computer that is running Microsoft Office Outlook 2003.

Outlook 2003 adds a fourth entry to the PR_FREEBUSY_ENTRYIDS property. PR_FREEBUSY_ENTRYIDS is a multi-valued MAPI property that is stored on the Inbox folder. CDO expects three entries. The unexpected fourth entry causes heap corruption that causes OWA or the third-party program to stop responding.

Hotfix information

A supported fix is now available from Microsoft, but it is only intended to correct the problem that this article describes. Apply it only to systems that are experiencing this specific problem.

To resolve this problem, contact Microsoft Product Support Services to obtain the fix. For a complete list of Microsoft Product Support Services phone numbers and information about support costs, visit the following Microsoft Web site:Note In special cases, charges that are ordinarily incurred for support calls may be canceled if a Microsoft Support Professional determines that a specific update will resolve your problem. The usual support costs will apply to additional support questions and issues that do not qualify for the specific update in question.

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.You can also download this hotfix from the Microsoft Download Center. To do so, visit the following Microsoft Web site: This hotfix has been modified so that you can install this hotfix in an Exchange organization on a computer that only permits administrators to log on to the computer. The hotfix files were not changed; only the installer scripts were changed so that if you already installed the hotfix, you do not have to remove the earlier version to install the new version. The new name of the hotfix is Exchange5.5-KB818709-v2-x86-enu.exe.
If Exchange 5.5 OWA is set up to use a front-end/back-end server configuration, install this hotfix on the front-end server in addition to the back-end server. If only the OWA component is installed on an IIS server, apply this hotfix to the IIS server as well.

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

For a Microsoft Exchange 2000 Server version of this article, click the following article number to view the article in the Microsoft Knowledge Base:For a Microsoft Exchange Server 2003 version of this article, click the following article number to view the article in the Microsoft Knowledge Base: