Help Required for Sendmail

["Ajay Anand" <ajaya@xxxxxxxxxxxxxxx>]

Hi Friends,

I am new to the group and infact somehow new to Linux also. I am trying to
configure sendmaila and am directly connected to Internet thru modem. I had
configured my linux server with VSNL DNS server. I am having Linux Redhat
7.0

When I am trying to send mail outside, I am getting an error "deffered, host
name not found"

I have no clue about this and I am not having any dns or wins server at my
llinux server. Pls let me know how to resolve this problem

Thanks in advance

Ajay Anand