PowerShell – Howto Update the GAL and OAB in Exchange

This morning I was asked to update the Global Address List and Offline Address Book in an Exchange environment.
You could wait for Exchange to do it automatically (the default schedule is once a day) but what when you want to force the update to take place right now?

Well… again here comes PowerShell to the rescue:

So now that the GAL is updated there could be some users that are using a Offline Address Book (OAB).
So, what is the PowerShell command to update this?

And last… when you update the OAB you’ll also need to update let the Client Access Server know that there is an updated OAB.
Also this you can accomplish through PowerShell:


  1. Guenther Schmitz says:

    is there a powershell way to save the gal into a users contact list?

  2. Dragunbayne says:

    Thanks for this. I had found the info to update the OAB elsewhere, but no mention of the update GAL. You rock!

  3. Jeff Wouters says:

    Hello Dragunbayne,
    Glad you found it useful 🙂

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