Send mail using ASP.NET

< body>
    < form id="form1" runat="server">
   < div>       
            < div style="width: 408px; height: 242px">                
               < strong> To:</strong>< asp:TextBox ID="ToText" runat="server" Width="263px"></asp:TextBox>              
                 <br />
               < strong> From:</strong> 
               < asp:TextBox ID="FromText" runat="server" Width="256px">< /asp:TextBox>              
               < strong>  Subject:</strong>
               < asp:TextBox ID="SubjectText" runat="server" Width="244px" >< /asp:TextBox> <br />              
                < strong> Message:</strong>                   
   < asp:TextBox ID="MessageText" runat="server" Height="106px" Width="310px">< /asp:TextBox> <br />
                <br />            
 < asp:Button ID="Buttsend" runat="server" Text="Send" Width="77px" OnClick="Buttsend_Click" />
   <asp:Label ID="Label2" runat="server">               < asp:Button ID="Buttcancel" runat="server" OnClick="Buttcancel_Click" Text="Cancel" >              
               < /asp:Button>                
                < asp:Label ID="Label1" runat="server">        < /div>    
    < /div>
    < /form>
< /body>

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.Mail;

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

    }
    protected void Buttsend_Click(object sender, EventArgs e)
    {
        MailMessage mm = new MailMessage();
        SmtpClient smtp = new SmtpClient();
        mm.From = new MailAddress(FromText.Text);
        mm.To.Add(new MailAddress(ToText.Text));
        mm.Subject = SubjectText.Text;
        mm.Body = MessageText.Text;
        mm.IsBodyHtml = true;
        smtp.Host = "smtp.gmail.com";
        smtp.EnableSsl = true;
        System.Net.NetworkCredential NetworkCred = new System.Net.NetworkCredential();
        NetworkCred.UserName = "your gamail.com";//write your gmail user name
        NetworkCred.Password = "your password";// write pass word            smtp.UseDefaultCredentials = true;
        smtp.Credentials = NetworkCred;
        smtp.Port = 587; //Gmail port for e-mail 465 or 587
        smtp.Send(mm);
        Label2.Text = "succecc fully send";
    }

    protected void Buttcancel_Click(object sender, EventArgs e)
    {
        Label1.Text = "try again";
    }
}