I had a request to export mailbox permissions on an Exchange 2003 Exchange server to see who has rights on certain individuals’ mailboxes and what rights these groups and people have on the said mailboxes.
I found a tool called ADModify that did the job perfectly. The tool exports the data to xml. Open it with Microsoft Excel and choose “Open as XML Table”. Then use the filters at the top to view what the permissions are and what permissions each object holds on the particular mailbox.
The download link to ADModify is here.
A very nice tutorial on using the tool to only export mailbox rights can be found here.
Note that the tool may be used to do bulk permission changes to mailboxes etc. Please read the tutorial before using the tool as the last thing you would want to do is add or delete permissions on 1000’s of mailboxes.