sendmail using System.Net.Mail ....

using System;
using System.Data;
using System.Configuration;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;
using System.Net;
using System.Net.Mail;
using System.Drawing;
using System.IO;

public partial class _Default : System.Web.UI.Page
{
   protected void Page_Load(object sender, EventArgs e)
   {
       if (!IsPostBack)
       { }
   }
   protected void btSend_Click(object sender, EventArgs e)
   {
       try
       {
         
           MailMessage mM = new MailMessage();
           mM.From = new MailAddress(txtFrom.Text);
           mM.To.Add(txtTo.Text);
           mM.Subject = txtSub.Text;
           mM.Body = txtMsg.Text;
           mM.IsBodyHtml = true;
           mM.Priority = MailPriority.High;
           SmtpClient sC = new SmtpClient("smtp.mail.yahoo.com");
           sC.Port = 587;
           sC.Credentials = new NetworkCredential("YahooId", "Yahoo Password");
           //sC.EnableSsl = true;
           sC.Send(mM);
           lbReport.Text = "Mail Send Successfully";
           lbReport.ForeColor = Color.Green;

       }
       catch(Exception ex)
       {
           lbReport.Text = ex+"Mail Sending Fail's";
           lbReport.ForeColor = Color.Red;
       }

   }
}