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Changing OWA time out on an Exchange 2007 and 2010 Computers

Posted by Milind Naphade on 22/10/2009

Exchange Server 2007 OWA will automatically time out for the security purposes. This feature has been designed to restrict unauthorized access to any mailbox when the user is using a public or shared computer. You can select this option before you logon to your mailbox:

Though this feature is good for security reasons it may be annoying for many users who use OWA regularly and they may not want to enter the password several times after the time out. This can settled down with a simple registry tweak on the CAS box that runs your Internet facing OWA site. This can be done by following registry modification.


Name: PublicTimeout


Value: {value in minutes} (This value is 15 minutes by default)


The above suggestion applies only when the user selects the Public Computer option from the OWA logon screen. For the user who select the Private Computer from the logon screen you might want to modify:

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\MSExchange OWA

Name: PrivateTimeout


Value: {value in minutes} (This value is 8 hours by default)

If you don’t see the DWORD values named, PublicTimeout and PrivateTimeout then you have create then manually.

2 Responses to “Changing OWA time out on an Exchange 2007 and 2010 Computers”

  1. David said

    Are the defaults built-in and not listed in the registry?

    On Exchange 2007, I see the branch mentioned here, although it is “MSExchange OWA” with a space instead of no space. The branch does not have the values indicated. I’m assuming you add the values (name & value) in to override the defaults?

  2. Hi David,
    Sorry for the delayed response. It was a typo. Thanks for bringing it to notice. I have corrected it now. Also, to answer your second question, Yes, you need to create the values to override the defaults.

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