How to Manage Offline Address Book File Sizes


In Offline Address Book version 4 (OAB v4), Microsoft® Exchange Server 2003 limits the size of single and multiple valued attributes to prevent abnormally large records from being included in the offline address book. On offline address book servers that run Microsoft Exchange Server 2003 Service Pack 2 (SP2), you can configure Exchange Server to limit the size of specific property types within offline address book download files.


These settings only apply to OAB v4 files generated by Exchange Server 2003 SP2 and used by Microsoft Office Outlook® 2003 SP2 and later. Previous offline address book versions used by earlier Outlook clients are unaffected.

Before You Begin

If you see MSExchangeSA event 9320 and MSExchangeSA event 9359 in the Application Log, consider configuring the size limits of specific property types. The following table lists the four property types that you can limit and the default values and lower values that you can configure in the registry.

Registry key name Description Default value (bytes) Lower limit (bytes)

OAL V4 String Limit

Single valued text-based Active Directory properties such as Display name, Telephone number, and Office location.



OAL V4 Binary Limit

Single valued binary-encoded Active Directory properties such as userCert.



OAL V4 String Multi Value Limit

Multi-valued text-based Active Directory properties such as Email Addresses, and Business and Home Telephone



OAL V4 Binary Multi Value Limit

Multi-valued binary-encoded Active Directory properties such as userSMIMEcertificate and userCertificate.



If the registry key does not exist for a specific value, the default value is used. If the registry key is set to a value lower than the lower limit, the lower limit value is automatically used.


For Exchange Server and Outlook to properly operate, some attributes are not subject to having their size limited.

For additional information about this feature, see "Managing Offline Address Book File Sizes" in Using Offline Address Books.


This article contains information about editing the registry. Before you edit the registry, make sure you understand how to restore the registry if a problem occurs. For information about how to restore the registry, view the "Restore the Registry" Help topic in Regedit.exe or Regedt32.exe.


To manage the size of offline address book files

  1. On the Exchange server, start Regedit.exe.

  2. Open the following registry key:


  3. Right-click Parameters, point to New, and then click DWORD Value.

  4. For the new value name, type the name of the value you want to configure.

  5. Double-click the Value Name you created in the previous step. In Value data, type an appropriate value for maximum attribute size in bytes.

  6. Click OK.

  7. Close the registry editor.

Before you edit the registry, and for information about how to edit the registry, see Microsoft Knowledge Base article 256986, "Description of the Microsoft Windows Registry."

For More Information

For additional information about how to minimize the effect that offline address book downloads have on your network, see "Minimizing Offline Address Book Download Effect on Network" in Using Offline Address Books.

For additional information about configuring the offline address book file size setting, see "Managing Offline Address Book File Sizes" in Using Offline Address Books.