The following Sample Code is the code which can be used to send mails through ASP.Net C#.... its a working code for me.....

using System;
using System.Data;
using System.Configuration;
using System.Collections;
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.Mail;

public partial class Default : System.Web.UI.Page
{
  protected void Page_Load(object sender, EventArgs e)
  {
  }
  protected void Button1_Click(object sender, EventArgs e)
  {
//Calling the function SendMail
    Response.Write( SendMail("
  This e-mail address is being protected from spambots. You need JavaScript enabled to view it
 ","
  This e-mail address is being protected from spambots. You need JavaScript enabled to view it
 ","
  This e-mail address is being protected from spambots. You need JavaScript enabled to view it
 ","Test Mail","Test Mail Body"));
  }

  public string SendMail(string toList, string from, string ccList, string subject, string body)
  {
      MailMessage message = new MailMessage();
      SmtpClient smtpClient = new SmtpClient();
      string msg = string.Empty;
      try
      {
          MailAddress fromAddress = new MailAddress(from);
          message.From = fromAddress;
          message.To.Add(toList);
          if (ccList != null && ccList != string.Empty)
              message.CC.Add(ccList);
          message.Subject = subject;
          message.IsBodyHtml = true;
          message.Body = body;
          smtpClient.Host = "mail.server.com";
          smtpClient.Port = 25;
          smtpClient.UseDefaultCredentials = true;
          smtpClient.Credentials = new System.Net.NetworkCredential("
  This e-mail address is being protected from spambots. You need JavaScript enabled to view it
 ", "password");         

          smtpClient.Send(message);
          msg = "Successful";
      }
      catch (Exception ex)
      {
          msg = ex.Message;
      }
      return msg;
  }

}
 

For Details Visit Here
--
Thanks and Regards
Meetu Choudhary