Email Sending Code Form Server Side Asp.net

Email  Sending Code Form Server Side Asp.net

using System;
using System.Collections.Generic;
using System.Web;
using System.Linq;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Net;
using System.Net.Mail;
using System.Net.Mime;

public partial class MAil : System.Web.UI.Page
{
 protected void Page_Load(object sender, EventArgs e)
    {

     }
 protected void btnSubmit_Click(object sender, EventArgs e)
    {
        #region Remotehost


        //--------FOR REMOTE HOST
        try
        {
            if (Page.IsValid)
            {

                const string SERVER = "localhost";
                MailMessage oMail = new MailMessage();
                oMail.From = new MailAddress("contact@mail.co");
                oMail.To.Add(new MailAddress("do_not_reply@mail.co"));
                oMail.Subject = TextBox2.Text;
                oMail.IsBodyHtml = true; // enumeration
                oMail.Priority = MailPriority.High; // enumeration
                oMail.Body = "<b>Sender's Name:-</b></b>" + TextBox1.Text + "<br/></b>" + "<b>Sender's Email:-</b></b>" + TextBox2.Text + "</b><br/>" + "<b>Sender's Mobile:-</b></b>" + TextBox3.Text + "</b><br/>" + "<b> Sender's Subject:-</b></b>" + DropDownList1.SelectedValue + "<br/></b>" + "<b>Sender's Message:-</b></b>" + TextBox4.Text + "<br/></b>" + "<b>Others:-</b></b>" + TextBox6.Text;
                SmtpClient sC = new SmtpClient(SERVER);
                sC.EnableSsl = false;
                ContentType contentType = new ContentType();
                contentType.MediaType = MediaTypeNames.Application.Octet;
                contentType.Name = "xml.xml";
                sC.Send(oMail);
                oMail = null; // free up resources
                ScriptManager.RegisterStartupScript(this, GetType(), "showalert", "alert('EMail Sent');", true);


                TextBox1.Enabled = false;
                TextBox2.Enabled = false;
                TextBox3.Enabled = false;
                TextBox4.Enabled = false;

            }


            TextBox1.Text = "";
            TextBox2.Text = "";
            TextBox3.Text = "";
            TextBox4.Text = "";

        }
        catch (Exception ex)
        {
            ScriptManager.RegisterStartupScript(this, GetType(), "showalert", "alert('Error Found');", true);

        }
    }