using System;
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using System.IO;
using System.Net.Sockets;
using System.Threading;
using System.Net;
using System.Web;
namespace RawMail
{
    public partial class Form1 : Form
    {
        public static string SmtpServer="mail.domain.com";
        public Form1()
        {
            InitializeComponent();
        }
        private void Form1_Load(object sender, EventArgs e)
        {
        }
        private void button1_Click(object sender, EventArgs e)
        {
            scrlog.Clear();
            bool _sonuc=Send(alici.Text,icerik.Text);
            if (_sonuc == false)
            {
                sondurum.Text = openFileDialog1.FileName + "Gönderim Hatası.";
            }
            else
            {
                sondurum.Text = openFileDialog1.FileName + "Gönderildi";
                alici.Text = "";
                icerik.Text = "";
                scrlog.Text = "";
            }
        }
        private void Form1_FormClosing(object sender, FormClosingEventArgs e)
        {
        }
        private enum SMTPResponse : int
        {
            CONNECT_SUCCESS = 220,
            GENERIC_SUCCESS = 250,
            DATA_SUCCESS = 354,
            QUIT_SUCCESS = 221
        }
        private void LogTut(string _bilgim)
        {
            string _metnim = DateTime.Now.Hour + ":" + DateTime.Now.Minute + ":" + DateTime.Now.Second +
                    " -> " + _bilgim + "\r\n";
            scrlog.Text = scrlog.Text + _metnim;
            scrlog.SelectionStart = scrlog.Text.Length;
            scrlog.ScrollToCaret();
            Application.DoEvents();
        }
        private bool Send(string _kime,string _govde)
        {
            IPHostEntry IPhst = Dns.Resolve(SmtpServer);
            IPEndPoint endPt = new IPEndPoint(IPhst.AddressList[0], 25);
            Socket s = new Socket(endPt.AddressFamily, SocketType.Stream, ProtocolType.Tcp);
            s.Connect(endPt);
            if (!Check_Response(s, SMTPResponse.CONNECT_SUCCESS))
            {
                s.Close();
                return false;
            }
            Senddata(s, string.Format("HELO {0}\r\n", Dns.GetHostName()));
            if (!Check_Response(s, SMTPResponse.GENERIC_SUCCESS))
            {
                s.Close();
                return false;
            }
            Senddata(s, string.Format("MAIL From: {0}\r\n", _kime));
            if (!Check_Response(s, SMTPResponse.GENERIC_SUCCESS))
            {
                s.Close();
                return false;
            }
            string _To = _kime;
            string[] Tos = _To.Split(new char[] { ';' });
            foreach (string To in Tos)
            {
                Senddata(s, string.Format("RCPT TO: {0}\r\n", To));
                if (!Check_Response(s, SMTPResponse.GENERIC_SUCCESS))
                {
                    s.Close();
                    return false;
                }
            }
            Senddata(s, ("DATA\r\n"));
            if (!Check_Response(s, SMTPResponse.DATA_SUCCESS))
            {
                s.Close();
                return false;
            }
            StringBuilder Header = new StringBuilder();
            Header.Append(_govde);
            Header.Append("\r\n");
            Header.Append(".\r\n");
            Senddata(s, Header.ToString());
            if (!Check_Response(s, SMTPResponse.GENERIC_SUCCESS))
            {
                s.Close();
                return false;
            }
            Senddata(s, "quit\r\n");
            Check_Response(s, SMTPResponse.QUIT_SUCCESS);
            s.Close();
            return true;
        }
        private void Senddata(Socket s, string msg)
        {
            byte[] _msg = Encoding.ASCII.GetBytes(msg);
            s.Send(_msg, 0, _msg.Length, SocketFlags.None);
            LogTut(msg);
        }
        private bool Check_Response(Socket s, SMTPResponse response_expected)
        {
            string sResponse;
            int response;
            byte[] bytes = new byte[1024];
            while (s.Available == 0)
            {
                System.Threading.Thread.Sleep(100);
            }
            s.Receive(bytes, 0, s.Available, SocketFlags.None);
            sResponse = Encoding.ASCII.GetString(bytes);
            response = Convert.ToInt32(sResponse.Substring(0, 3));
            LogTut(sResponse);
            if (response != (int)response_expected)
                return false;
            return true;
        }
        private void button2_Click(object sender, EventArgs e)
        {
            try
            {
                openFileDialog1.ShowDialog();
                string _dosyaYOL = openFileDialog1.FileName;
                icerik.Text = File.ReadAllText(_dosyaYOL).ToString();
                int _toYERI = 0;
                int _dene = 0;
                int _baslamaYERI = 0;
                bool _yerBULUNDU = false;
                while (_yerBULUNDU == false)
                {
                    _dene=icerik.Text.IndexOf("To:",_baslamaYERI) + 3;
                    if (icerik.Text.Substring(_dene - 4, 5).Contains("-To"))
                    {
                        _yerBULUNDU = false;
                        _baslamaYERI = _dene;
                    }
                    else
                    {
                        _yerBULUNDU = true;
                        _toYERI = _dene;
                    }
                }
                int _bitisYERI = icerik.Text.IndexOf("com", _toYERI) + 3;
                int _alinacak = _bitisYERI - _toYERI;
                alici.Text = icerik.Text.Substring(_toYERI, _alinacak).Replace("<", "").Replace(">", "").Replace(" ", "");
                int _toplamBOYUT=Convert.ToInt32(icerik.Text.Length);
                iletiboyutu.Text =(_toplamBOYUT/1000).ToString("n0") + " KByte";
            }
            catch
            {
                MessageBox.Show("İleti okunamadı yada 8bit,base64 gibi bir yöntemle kodlanmış olabilir.");
            }
        }
        private void progressBar1_CursorChanged(object sender, EventArgs e)
        {
            Application.DoEvents();
        }
    }
}
<a href="http://www.codelama.com/media/wpics/2010/11/Logo_C_Sharp.png"><img class="alignnone size-full wp-image-293" title="Logo_C_Sharp" src="http://www.codelama.com/media/wpics/2010/11/Logo_C_Sharp.png" alt="" width="256" height="256"></a>