Know your ExMerge Lessons?

Some interesting links that give explanations over Exchange Server ExMerge tool and how it can help:
1- EXMerge is your friend

2- Some Questions and Answers About the Exmerge Utility:

What Are the Possible Uses of Exmerge?
You can use Exmerge to extract mail from a damaged private information store. Exmerge puts this mail into .pst files that you can import back into an undamaged private information store.
You can use Exmerge to locate and remove a specific e-mail message from the private information store (for example, virus mail).
You can use Exmerge to migrate users between different organizations and sites by copying the users' mail to .pst files that you can then import into the new organization or site.
You can use Exmerge to extract folder rules.
In some situations, you can even use Exmerge as a brick-level backup agent, although Exmerge does not have the ability to write the data to a backup tape. (More)

3- Using EXMERGE To Delete Message From Your Exchange Server :

One question that seems to come up a lot is “How can I delete a message from all the users mailboxes”, this question gets asked for many reasons, such as someone sent an email to the wrong group of people, you know that a message is in your system that contains an attachments that you do not want your users opening, you can probably think of a few more reasons... More

4- How can I delete all occurrences of a message from a Microsoft Exchange Server 2003 mail database?

Although you can recall sent messages in Exchange, recalling a message doesn't reliably delete all occurrences of it. Sometimes you'll want to remove all traces of a message--for example, when a former employee sends a malicious email message to current employees. You can use the Mailbox Merge Wizard (Exmerge) utility... More

5- Cleaning the Nasty Stuff Off Your Exchange Server