SendMail without password

Hi to all,
I have a code to send mail but it should need exact password of the mailid. like below
 
private
void Method4()

    {

        try

        {

        System.Net.Mail.MailMessage
mail = new System.Net.Mail.MailMessage();



        string fmadd = "from@yahoo.com";



        string toadd = "to@yahoo.co.in";



        string smtpser =
"smtp servername";



        string username = " Go to the complete details ...