Before we can use exmerge we need to do two things: Change permissions on the store as described in How to change permissions on your mailbox store Download Exmerge from Download details: Microsoft Exchange Server Mailbox Merge Wizard (ExMerge) After you have changed permissions on the store and downloaded Exmerge unpack the download to a directory of your choice. The download contains 4 files: The EULA Exmerge.exe Exmerge.ini Mailbox Merge Wizard (ExMerge).doc We need to copy the Exmerge.exe and the Exmerge.ini to the bin folder inside of the Exchange directory. In my case this is D:\Program Files\Exchsrvr\bin. After you have done that we are going to run the Exmerge.exe from the bin folder. Start Exmerge and click next Choose the Two Step procedure. Choose Extract data... Fill in the server name. The rest can remain empty but if you want to change some options click on options. In the Mailbox Merge Wizard (ExMerge).doc there is more information about the options. Select the mail boxes you want to include in your exmerge procedure. I choose 'Select all' and choose next. If you have different languages in your Lan you can choose to use 'Use last mailbox login locale'. I have only English so I do not choose that. Next... Choose a folder where you want the pst files to be stored. Be sure to include this folder in your regular backup! The last important part is that you save your settings. Each time you run the Exmerge wizard you must save the settings. Those settings are stored in the exmerge.ini file. And this is what happens if you do not change the permissions on the store according to the article I mentioned earlier. Normally you should see no failures. My guess is that you want to automate this process so that it runs from the task scheduler every night. Create a batch file that contains the following lines and save it as exmerge.bat in a folder on your server. cd 'C:\Program Files\Exchsrvr\bin\'ExMerge.exe -b The -b switch tells exmerge to run in a mode without the GUI. You can now schedule the batch file in the task scheduler.