Laeeq Qazi's Exchange Server Blog

Exchange Server blog

Manually Generating Offline Address Book on Exchange 2007/2010

An Exchange offline address book (OAB) is an Address Book that contains one or more address lists. It is availalble to Exchange Client softwares (e.g Outlook 2007) when users are not connected to Exchange Server and are offline.

OABs are not generated frequently in  a day because OAB generation process consumes much system resources if they contain hundreds of email addresses. Instead they are normally generated once or twice in a day depending upon the size of the OAB and need of the organization owning that OAB.

Sometimes its necessary to immediately generate the OAB when a new email address is added to Exchange System, so that the new email address is immediately available to outlook (or) other clients through downloading the latest OAB.

For immediate OAB generation and distribution (both PF, and web based distribution through CAS) I do following steps:

1. Run Update-OfflineAddressbook “offline address book”  in Exchange Management Shell. e.g

Update-OfflineAddressbook “Default offline address book”

2. Restart System Attendant Service on the OAB Generation Server (Mailbox Server). This service is responsible for generating the OAB by communicating with Active Directory infrastructure.

3. Either run following command in EMS

Update-FileDistributionService “CASServerName”

or just restart File Distribution Service on CAS Server.

File distribution service copies the OAB from the Mailbox Server, where System Attendant Service puts OAB in a shared folder “C:\Program Files\Microsoft\Exchange Server\ExchangeOAB”. Outlook clients then download the OAB from CAS published OAB Virtual Directory.

I hope that this post is helpful for you.

Best regards,


February 13, 2010 - Posted by | Exchange 2007, Exchange 2010


  1. This is very helpful – thanks!

    Comment by Wahab | May 19, 2010 | Reply

    • Thanks Wahab for your appreciation.

      Laeeq Qazi

      Comment by exchangegeek | May 20, 2010 | Reply

  2. saved my bacon thanks

    Comment by chris | November 15, 2011 | Reply

  3. Very helpful. Thanks!

    Comment by Greg | April 17, 2012 | Reply

  4. Great, thanks Laeeq 🙂

    Comment by Gary M | May 29, 2012 | Reply

  5. Very clear and helpful!

    Comment by pjcvsi | August 30, 2012 | Reply

  6. OAB Generates ok in MBX but get FDS erro on CAS server ( 1021 ) even with restaring FDS


    Comment by Naser | October 14, 2012 | Reply

  7. Hello there! Would you mind if I share your blog with my zynga group?
    There’s a lot of folks that I think would really appreciate your content.

    Please let me know. Many thanks

    Comment by Broderick Thibault | December 7, 2013 | Reply

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