protected void Button1_Click(object sender, EventArgs e)
    {
       MailMessage mm = new MailMessage();
        try
        {
            mm.From = "gopiyadavalli@yahoo.com"; // this is ur mail ID
            mm.To =txtto .Text.ToString();  
           

            mm.Body = txtmsgbody.Text.ToString(); 
            mm.Subject = txtsub.Text.ToString();
            System.Web.Mail.SmtpMail.Send(mm); 
            lblmsg.Text = "Email successfully sent.";
        
        }
        catch (Exception ex)
        {
            lblmsg.Text = "Send Email Failed." + ex.Message;
        }
   
    }