How to Kill an Exchange 2003 Session/Logon

I'd spin up an instance of an older version of Windows, install the Exchange 2003 management tools, and continue with the decommissioning procedure just to be safe. I'm assuming this is a production environment, and I don't think I'd toy around with deleting records via ADSIEdit.

In Exchange 2003, databases are always child objects of Exchange servers; so you'l find them in the directory tree with a structure like

 <Administrative Group Name>
   <Servers>
     <Server Name>
       <Information Store>
         <Storage Group Name>
           <Database Name>

This changed in Exchange 2010, where databases are higher-level objects, and are no longer tied to a specific server.

So, yes, that's the right place where you will find an Exchange 2003 public folder database, and the right place where you can delete it.