Outlook may be slower to resolve names because there are no .oab files locally

Original KB number:   2746896


In Microsoft Outlook, when you attempt to resolve the email address for someone in your Microsoft Exchange organization, the process may take longer than expected. Or, if you are working offline, you are unable to resolve any names for people in your Exchange organization.


This problem occurs if Outlook is not using local Offline Address Book (OAB) files to resolve names. Instead, Outlook is performing name resolution using the online Global Address List (GAL). If you are in Online mode, this is to be expected. However, if you are in Cached mode, the default configuration is to always download the OAB locally and use it for name resolution.


To resolve this problem, download the Offline Address Book using the following steps (depending on the Outlook version).

  • Outlook 2010 or later versions

    1. Select the Send/Receive tab on the Ribbon.
    2. Select Send/Receive Groups and then select Download Address Book.
    3. Select OK.
  • Outlook 2007 or Outlook 2003

    1. On the Tools menu, point to Send/Receive, and then select Download Address Book.
    2. Select OK.

See the following article if you are unable to download the OAB.

HTTP version of the Outlook Offline Address Book (OAB) does not download


If the OAB does not automatically download and you have to manually download the OAB each time (using the above steps), check for the existence of the DownloadOAB value in the registry. The following article provides complete details on this registry value.

Administering the offline address book in Outlook

More information

Use the following steps to determine if you are using the online GAL for name resolution instead of local .oab files.

  1. Start Outlook.

  2. Select the Address Book icon.

  3. In the Address Book dialog box, right-click drop-down under Address Book and select Properties (The screenshot for this step is listed below).

    Screenshot of the Properties option of Address Book.

  4. In the Global Address List dialog box, examine the text in The current server is: box (The screenshot for this step is listed below).

    Screenshot of the Global Address List dialog box.

    • If you see a local file path, as shown in the above figure, you are downloading the .oab files locally.
    • If you see the name of a server, you are currently not downloading .oab files locally.

The location of the files on your computer varies according to your Outlook version and the version of Windows on which Outlook is installed. The default location for .oab files is provided below.

  • Outlook 2010 and later versions

    • Windows 10, Windows 8.1, Windows 8, or Windows 7

      %userprofile%\AppData\Local\Microsoft\Outlook\Offline Address Books<guid>

    • Windows XP (Outlook 2010 only)

      %userprofile%\Local Settings\application data\Microsoft\Outlook\Offline Address Books<guid>


      <guid> in the above folder path varies between Exchange organizations. The folder name, for example, will look like 0a1f33a0-dbeb-4007-92e3-57926c848000

  • Outlook 2003 and Outlook 2007

    • Windows 10, Windows 8.1, Windows 8 or Windows 7


    • Windows XP

      %userprofile%\LocalSettings\application data\Microsoft\Outlook