Eseutils on Exchange 5.5

There are several approaches. The most recommended and successful is to:
1. Clear off disk space on the server. Even if this means deleting shares that will be restored later through a tape restore.

2. Run the Exchange Performance Optimizer to help you optimize server performance. Not only can you safely optimize exchanges registry entries, you can move priv and pub stores to a different directory (it makes recommendations based upon space). The optimizer does this safely and you can take their suggestions or input your own location to move these stores.

3. After the stores are moved, run the eseutils and pare down your stores. You can leave the directories where they are, or run the optimizer again and move them back to their familiar locations.

Good luck,
Obytes

The following articles can be found at support.microsoft.com, and explain how to defragment .edb files on servers that do not have Exchange:
255035
244525

As for how long it takes to defragment, Microsoft says about 10GB per hour. If you want to confirm, check out:
http://www.microsoft.com/technet/treeview/default.asp?url=/technet/prodtechnol/exchange/exchange55/reskit/exc08.asp
(should be no spaces in this link)