using System.Net.Mail.SmtpClient;

using System.Net.MailMessage; 

protected void btnSendmail_Click(object sender, EventArgs e)
      {
        
        
        SmtpClient smtpClient = new SmtpClient();
        MailMessage message = new MailMessage();

        try
        {
            MailAddress fromAddress = new MailAddress(txtEmail.Text, txtName.Text);

            
            
            smtpClient.Host = "localhost";

            
            smtpClient.Port = 25;

            
            message.From = fromAddress;

            
            message.To.Add("admin1@yoursite.com");
            message.Subject = "Feedback";

            
            
            
            message.CC.Add("admin1@yoursite.com");
            message.CC.Add("admin2@yoursite.com");

            
            message.Bcc.Add(new MailAddress("admin3@yoursite.com"));
            message.Bcc.Add(new MailAddress("admin4@yoursite.com"));

            
            
            message.IsBodyHtml = false;

            
            message.Body = txtMessage.Text;
         
            
            smtpClient.Send(message);

            lblStatus.Text = "Email successfully sent.";
        }
        catch (Exception ex)
        {
            lblStatus.Text = "Send Email Failed." + ex.Message;
        }
      }