how i use socket programing for connecting the domain server ?

[avinashibs]

using socket :-

how i use the socket for connecting the domain server,
e,g :-
i have an account on gmail
emailid :- xyx@gmail.com
pass:- 1354

how i will check my account is exit on that particular domain ......

[avinashibs]

how i use socket programing for connecting the domain server using vb.net ?