Email from client side with attachment

Hi,

I was trying to find out what is the best way for a client to send a
mail to centralised support group? I have C# client code. This one runs
in client side. I want to add a feature to the program to send some
data file as email by choosing menu option.

Based on what I read and gather from this group, I could use MAPI. But
I have couple of questions;
1. MAPI required to specify the exchange server name and my client code
will not be aware of the exchange server name. I do not want to prompt
the user to enter the exchange name since most the end users will not
have an idea.
2. I hope everyone who runs my .net app are using outlook as their
email, is there a way to find out which email the client is using?

Thanks.