The local ” names.nsf” is designed for the user to put his personal contacts in it. This uses the Template pernames.ntf. This hold not only the address book entries for the user but also configuration settings such as connection / location documents. It also holds trusted certificates amongst other things. This file is created when you configure the user and is specific to that user.
The names.NSF located at the server is called the Domino directory (Template name Pubnames.ntf). You will be aware that the server requires an ID to work. Well the ID tells the server who it is. The Domino directory tells it what it can do and how it does it. The domain information is also contained here. This is all the information for users / Groups / Servers / Security / Authentication / Ceritifcates and a whole lot more. All the Domino servers in the same domain share this one database (names.nsf) and is the most important database in your Domino environment.
Now as for Client server environment….. This means that a lot of the processing for what you do in Lotus Notes is not done on the server. I will give you the easiest way to check this out.
In your Lotus Notes Client…… configured with your home server send an email (now guess where what servers sends that mail) run a message tracking request to check that you were right…. now change your HOME Server in your location document to point to another server. Now send another email. Now do a delivery report in a new mail (delivery option > delivery report > trace entire path). Then send your mail. You will see that your mail did not go through the server that your database is on.
This is a basic view at what is going on but you can see that connecting to a DB on one server does not mean you send mail through it….. Server and Client explained
I hope this helps.