How to Get user Access unique ID for Lnkedin with out Authen

Question

Hi Friends,

           I have created Desktop application. in this app. i have User Enail MailID or Mobile/Phone Numberusing any one of this how can i get user access ID(Unique ID)(This id is identify the particular(Exact) user) or User Access URL.

 Purpose of this :

I want to Post their walls or sending a mail to that particular user using this User access ID or URL with out any authentication.

So please can any one suggest me on this......

Thanks in Advance,
Mohan G