Here this is right from Microsoft it also includes Exchange 2000:
To perform an offline defragmentation of the database, perform the following steps.
NOTE: Microsoft recommends that you only perform an offline defragmentation of the database when you have performed an operation that caused a large number of objects to be removed from the database. Performing an offline defragmentation under any other circumstances may actually hurt database performance.
Stop the information store service:
In Control Panel, double-click Services.
Click the Microsoft Exchange Information Store service, and then click Stop. If a dialog box is displayed that states that additional services will be stopped, note the services that will be stopped, and then click OK.
Defragment the public and private information stores by using one of the following methods, as applicable:
In Exchange Server 5.5, to defragment the private information store, type eseutil /d /ispriv at a command prompt, and then press the ENTER key. To defragment the public information store, type eseutil /d /ispub at a command prompt, and then press the ENTER key.
In Exchange 2000, there is no /ispriv, /ispub, or /ds switch. You must specify the file name by typing the following at a command prompt
eseutil /d d:\path\file_name.edb and then pressing the ENTER key.
Start the information store service:
In Control Panel, double-click Services.
Click the Microsoft Exchange Information Store service, and then click Start.
Start any additional services that were stopped when you performed step 1.
Perform a full online backup of the information store databases.
Good Luck!