Software

Restore Exchange mailboxes with ExMerge

Fix corrupt Exchange mailboxes with ExMerge.


Microsoft’s Exchange Mailbox Merge utility, commonly known as ExMerge, is designed to facilitate e-mail migration. But it can also make backing up and restoring mailboxes much easier.

In response to a Technical Q&A question, TechRepublic members offered some general tips on backing up and restoring Exchange mailboxes, as well as information on using ExMerge to simplify the process. Here's a look at some of the members' suggestions, along with advice from TechRepublic's Exchange administrator based on his experience with ExMerge.

Member advice on tackling the task at hand
Facing the challenge of creating a corporate network, member Andrew Snelgrove wanted to know how to easily restore mailboxes.

“A complete restore from image works,” Snelgrove said, “but is there a way to restore mailboxes in a single-server environment?”

Member Nate McAlmond suggested that Snelgroveuse Microsoft’s ExMerge utility (which is included on the Exchange 2000 CD) to restore individual mailboxes on the server.

“ExMerge is really intended as a migration tool, but it makes the best [brick-level] backup for Exchange I’ve ever seen.”

To use ExMerge to back up mailboxes, McAlmond instructed Snelgroveto copy the Exmerge.ini file to the directory \Program Files\Exchsrvr\BIN\ and then use the two-step process to create .pst files from each of the mailboxes.

“You can even tell it which folders to skip, like the Deleted Items,” McAlmond said.

Another member, Mike Nelson, suggested that Snelgroveconsult the following resources:

He also provided the following instructions for restoring mailboxes in a single-server environment:
  1. After installing Exchange 2000, run Exchange System Manager and access the Private And Public Store Properties tab.
  2. In the Database tab, select This Database Can Be Overwritten By Restore.
  3. Dismount both Stores.
  4. Run Veritas BackupExec, NT Backup, or any Exchange backup program to restore Private and Public Stores.
  5. Mount both Stores.
  6. Run Exchange System Manager.
  7. Right-click on Mailbox Store and click Mailboxes and then choose Run Mailbox Cleanup Agent. This informs the system that the mailboxes are orphaned.
  8. Access Active Directory Users And Computers and create a new account for the mailbox you need to access.
  9. On the third screen of the wizard, deselect Create An Exchange Mailbox.
  10. Return to Exchange System Manager, right-click on the mailbox, and select Reconnect.
  11. After performing these steps, follow the instructions for getting service account access offered in this Microsoft Knowledge Base article.
  12. Install Outlook to view mailbox contents on the server or run ExMerge.

“This will allow you to export mailbox and public folder contents to a personal folder file (.pst) for importing into a new Exchange installation,” Nelson said.

ExMerge in the trenches
TechRepublic Exchange Administrator Mike Laun believes the easiest way for Snelgroveto accomplish his task is to script ExMerge to back up each mailbox. But he said it might not be the best tool for large organizations, because ExMerge is resource intensive. If the mailboxes are large, he said, using ExMerge to back up and restore items can be taxing on the server. In the case of larger organizations, Laun suggested using ExMerge to back up only mailboxes that contain critical data, such as mailboxes belonging to upper management or resource mailboxes.

Combating viruses with ExMerge
Laun said that ExMerge was originally released to deal with a particularly widespread e-mail virus (VBS/Loveletter), and one of the tool's most useful capabilities reflects that. ExMerge lets you pull individual items in a variety of ways. You can search by specific subject terms or by attachments. This is particularly handy when virus e-mails hit your server, because you can use ExMerge to delete all items off the server that contain particular words in the subject or body or that contain specific attachments.

You should be careful when you use ExMerge in this manner, however, because you can inadvertently delete legitimate messages.

“You have to search with the exact terms, word for word, space for space,” Laun said. “All of that has to be right on the money or you’re going to risk pulling out good messages.”

Similar caution is needed when you're pulling messages with attachments. You have to use the exact name of the file in the messages you want to delete.

Laun said ExMerge was a useful tool to have when the Melissa and I Love You viruses were being distributed because it allowed him to pull all of the suspect messages from the server in one fell swoop. The proof of the success of using ExMerge in this manner was the absence of support calls after all of the messages were deleted.

ExMerge and migrations
Laun also used ExMerge recently as part of an e-mail migration from one Exchange environment to another. With ExMerge, Laun was able to pull all user mailboxes from the server and save them to .pst files so that all of the messages stored on the server would be intact once the move was completed.

For migrations, ExMerge presents two options—a one-step process and a two-step process.

Laun said that in a one-step process, “ExMerge takes information from a mailbox on one server and pipes directly into a mailbox on another server.”

Laun used the two-step process for his migration, which he said is probably the most common option. With the two-step method, ExMerge exports data to .pst files that can then be imported into Exchange on the new server. ExMerge even preserves the folder structure when it exports the data.

ExMerge cannot, however, pull mailbox attributes.

“It doesn’t pull addresses like SMTP or X400,” Laun said. It just pulls elements like the calendar, the tasks, and the individual mail items.

Laun said ExMerge is also useful for performing brick-level backups.

“You can script it to back up individual mailboxes. You don’t have to use the interface. It can pull all the information out of the mailboxes on the Exchange server."

Unfortunately, you can't use ExMerge for public folders. You have to use another backup system to preserve the Public Store data.

Final word
Although ExMerge is best known for its role as an e-mail migration and antivirus utility, it can come in handy for a variety of routine administrative chores as well. Despite a few limitations, ExMerge is a great tool for backing up, migrating, and restoring user mailboxes.

“It’s truly the Exchange admin’s Swiss Army knife,” Laun said.

Additional reading
For more information about ExMerge, see this Microsoft Knowledge Base article.

 

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