How do you know which mailboxes are registered with the Auto Accept Agent?

Published Apr 14 2006 01:53 PM 1,991 Views

This is my 4th blog post on the subject of Exchange 2003 Auto Accept Agent. If you want to see previous posts, you can see them here: one, two and three.


The listings of Mailboxes that are registered on any given server are currently homed in the SystemMailbox. These registrations are populated by running the RegisterMailbox.vbs script and are listed as GUID items under the StoreEvents/Internal folder of the SystemMailbox as mentioned earlier. The inbox of the resource mailbox permanently contains an item "OnSaveForAutoAcceptAgent" (Subject, no sender) that is hidden. It is very important that one should not alter this in any way. If it is altered, the Sink will fail. If this message isn't hidden on the mailbox but is listed under the Root in Outlook the Sink will fail. This is probably due to a permissions issue.


There are 2 utilities that will allow you to open a resource mailbox and view properties of items in the mailbox including the GUID.



  2. Exchange Explorer

Exchange Explorer can be obtained from the Exchange SDK that will allow you to open a mailbox and view properties of items in the mailbox including GUIDs. More information regarding this application can be found at:


The Exchange SDK can be downloaded from


MFCMAPI can be obtained from


Here are the steps to use MFCMAPI to check the store event on the inbox folder of the resource mailbox.


Ensure that the user performing this process has "Receive As" rights on the Mailbox Store where the SystemMailbox resides. Follow article 821897 for more information on how to do this.


  1. Copy MFCMapi to the client machine that has Outlook running.

  2. Create an Outlook profile for the registered resource mailbox.  Make sure that you have "Prompt for a profile to be used" option check.

  3. Start the MFCMapi and click OK on the About MFCMapi window.

  4. On the MFCMapi window, click on Session menu and select Logon and Display Store Table.

  5. Select the Outlook profile that you just created.  This will open the mailbox table and the public folder.

  6. Highlight mailbox and click MDB > Open Store.  This will open the mailbox store.

  7. Expand Root Container > Top of Information Store.

  8. Highlight the Inbox folder and click Actions | Open Associated Contents Table.

  9. From the top pane, look under the Subject column.  You should have "OnSaveForAutoAcceptAgent".  If you don't see this hidden message, that means the mailbox did not get register with the Auto Accept Agent.

  10. Highlight the OnSaveForAutoAcceptAgent and click Actions > Save Message(s) To File. This will save all the properties of the message into text format.

  11. Select OK and choose the location to save the text file. 


Below is a screenshot of the "OnSaveForAutoAcceptAgent" hidden message as seen with MFCMAPI.



In order to view the GUIDs within the SystemMailbox, follow steps 1-7 and navigate to StoreEvents > internal folder. Double click the internal folder to view the GUIDs of the registered mailboxes. To log into the SystemMailbox mailbox, have a look at article 253784 for the steps. As another method MFCMAPI can be used to logon to the SystemMailbox without creating an explicit profile. Log into the SystemMailbox only as a measure of troubleshooting.


Hope this was helpful!


- Nagesh Mahadev

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