Microsoft Exchange Server

Who is my Microsoft Exchange Server?
How come when I try to use a address link in my outlook
express it says there are network problems preventing
connection to my Microsoft Exchange Server and to contact
my system administrator? What is that? How do I fix the
problem? Network problems? What network? I have no
problems with connecting to the internet, my outlook
express is all good. But when ever I try to email
pictures through my film factory program the same thing
happens. I have checked all the book I can understand and
I don't understand.
If you can give me some insight, that would be great.
thanks