When a user adds someone as a delegate of his/her mailbox and selects the option to have meeting requests go to the delegate, a hidden rule is created in the Inbox of the delegator. When you remove the delegate from the list the rule is deleted. But if the delegate isn’t removed before the delegee’s mailbox is deleted (presumably due to termination), the rule isn’t deleted. The delegate is removed from the Delegates tab so you can’t remove the rule, effectively orphaning the rule. Because the rule still exists, meeting requests will still be sent to the delegate. Since the mailbox doesn’t exist anymore, the meeting requestor will receive an NDR from a person they didn’t even invite to the meeting.

Microsoft’s solution is to use MDBView and go through the hidden items in the inbox until you find the corresponding rule and manually delete it. You can also use the better tool, MFCMapi, to do it. I wanted a better way to do it, and one that admins who don’t delve into raw MAPI viewers could use. So I wrote this WebDAV script that queries the target mailbox for the hidden items in the inbox, displays them in a table, and allows you No. to delete the message from the results window.

The delegate rule’s Rule Provider Content value is “Schedule+ EMS Interface.” If the delegator has multiple delegates who receive meeting requests (not that common) you won’t see multiple rules. There is only one rule, regardless of the number of recipients. If you don’t see an item with the Rule Provider Content Value above, then the user doesn’t have any delegates who receive meeting requests.

The script uses Exchange 2003 SP1’s ability to use the SMTP address in the URL, negating the need for a virtual directory for each SMTP namespace in your org. So you need SP1 for this to function. Just change the values near the top for the protocol and server name of your front-end or back-end server. I wrapped the script in a web page so it can be hosted on an IIS server and then you can just browse to it from anywhere. Note that it is not a server-side script. The code will be executed by the client and will prompt for credentials. Putting it in a web page is just a convenience. Just copy and paste it into a file, or download it here.