How do I…: Use EXMERGE to protect Individual users’ mailboxes?


For the third time this month I’ve gotten this email:

My email is gone, I need it back.
– Your boss

Now it wasn’t exactly like that, but it was pretty dang close. I have absolutely no idea how this keeps happening (though I am pretty sure it has something to do with him deleting it while “not doing anything”, and restoring from tape is getting old.

So I put a little thought into it, and I’ve got a “quick and (not so) dirty” solution.
ExMerge can be used to backup any mailbox on any server (it works remotely too) and you can schedule it to run as you please.

WARNING: Do not confuse this procedure for a proper method for protecting Exchange. This will only protect individual mailboxes, so if anything happens to the actual Mail Store in Exchange, you’re going to have trouble if you are not performing a proper “monolithic” Exchange backup.

First we need to get a current version of ExMerge for Exchange 2003 (what I am using at work, and what this article is based on, though the setps for prior versions of Exchange are pretty much the same). To get this we head over to Microsoft’s site and download it here.

Once we have the latest version of ExMerge, extract it from the download (use 7zip or similar compression software) and copy EXMERGE.EXE to the %Program Files%>Exchsrvr>bin folder of your Exchange server.

Now we need to configure the user account being used to do this to have access to the mailbox(es) that will be backed up (by default the Exchange Full Administrator permissions do not give you the right to open any other users’ mailbox).

Configuring EXMERGE

To perform Brick-Level backups of one or more mailboxes found on one Exchange server follow these steps:

  1. Navigate to the %Program Files%>Exchsrvr>bin folder of your Exchange server and double click ExMerge.exe.
  2. On the Welcome page click Next.
  3. On the “Procedure Selection” dialogue box, select “Export or Import (Two Step Procedure)”.
  4. On the “Two Step Procedure” dialogue box, select “Step 1: Extract data from and Exchange Server Mailbox”.
  5. In the “Source Server” dialogue box specify the name of your Exchange server. If you have a multiple domain environment you’ll need to specify the name and LDAP port number of your Domain Controller. Click Next.
  6. In the “Database Selection” dialogue box select the mailbox store you want to perform the action upon (Note: In a scenario where you only have one mailbox store you will not be presented with this page). Click Next.
  7. In the “Mailbox Selection” dialogue box select individual mailboxes or press the “Select All” button to select all mailboxes found in that store. In this example I will only select one mailbox. Note that you can also see the mailbox size next to the mailbox name. Click Next.
  8. On the “Locale Selection” dialogue box select the Locale that you would like to use to search the mailboxes. (Hebrew users take note: there are special steps that must be taken to use ExMerge with Hebrew language characters. Contact Microsoft for specific instructions). Click Next.
  9. Specify the path to the folder where you want to place the .PST files. This folder should reside on a different HD that the one where your mailbox stores are located, but this is only a recommendation for performance benefits, not a must. Also, make sure you have enough free space on that partition. Click Next.
  10. On the “Save Settings” dialogue box you can now save the settings you’ve configured so far, or you can just click Next. You can also change the name and location of the files used by ExMerge by clicking on the “File Names” button.
  11. After pressing Next the process will begin. This could take a considerable about of time depending on how many mailboxes you’ve selected and the size of the mailboxes.

Now, next time this user “does nothing” and loses all their email, I can simply restore is from this PST file (assuming that I have a recent copy). To ensure that there is always a recent copy available, we’d need to automate this process of using ExMerge, which I will cover in another post.

WARNING: Be aware of the following issues:

  • Security – ExMerge does not password-protect the .PST files it creates.
  • Storage Space – You need to consider how much space is required to store the .PST files and with what frequency you will have to purge the archived .PST files.
  • Overwriting .PST files – If there is no corresponding .PST file for the mailbox in the export folder, EXMERGE will create a new .PST file for the mailbox. The .PST file naming convention is [ALIAS].PST. If a .PST file for the mailbox already exists in the export folder, ExMerge will export only new message data from the mailbox to the .PST file. Therefore, you may want to purge the .PST files or move them to another directory so that ExMerge will create new .PST files when it runs next time.
  • Single Instance Architecture – When ExMerge exports mailbox data to a .PST file, you lose the benefit of the Single Instance message storage capability, so expect a mailbox’s newly created .PST file to be 10% to 50% larger than the mailbox itself (depending on how many messages in that mailbox are also in other mailboxes on the Exchange Server).



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