OWA Signature Size in Exchange 2007

In Exchange 2003 we had an issue with the Signature Size that could be entered in OWA.


The size was per  Code set to 4Kb, and we could modify the size by modifying the following Registry Key on the Exchange 2003 Server:




If we set this to a value of 16000 , and the Maximum Size Of the Signature is set to 16Kb.


Now with Exchange 2007, we have this size of 16Kb already hard coded, so we don’t have to modify it anymore using Registry Keys, it is not possible also anymore.


An analysis showed us that 16 Kb is a suitable size for a signature, as 1 Character is approximately 1 byte, we can have 16000 Characters, which we find as enough.


Even with the 16 Kb Limit we have right now, problems can still come up, the signature can be not showed entirely, text may be missing. The reason for this could be a font that is non Microsoft and takes a large amount of bytes ( larger then a normal Font ) and OWA 2007 cannot display this.


To check if the signature was correctly added with all it’s content to the Users Mailbox you can do the following:


1.) Open Internet Explorer and navigate to http://mfcmapi.codeplex.com .


2.) Download this tool ( it will be an executable file )


3.) Configure an Outlook Profile for the user you want to check the Signature, in

     Online mode.


4.) Start MFCMapi.exe


5.) Click OK, Session – Log on and display store table – Select the Users Profile.


6.) Doubleclick the Users Mailbox, a new window will be opened.


7.) Right click the Root Container – Open Associated Contents Table

     ( a new window will be opened )


8.) Sort by class, and search for the following Property

      “IPM.Configuration.OWA.UserOptions”  and select this.



9.) After selecting this property, take a look in the Lower Pane, sort after TAG and

     search for the following : 0x7C070102 – This should have a name of



10.) Right click the property and click Edit, you will be able to copy the content out,

       and check if the Signature was added correctly.



 If you have any questions, please send me an Email to patrisel@microsoft.com



Comments (1)

  1. Cristian says:

    Genial, pude solucionar un problema gracias a esta data.

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