How to receive mail from pop3+ssl server with C# on mobile.

using System;
using System.Linq;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Text;
using System.Windows.Forms;
using System.Net.Sockets;
using System.Net;
using System.IO;
using System.Runtime.InteropServices;
using System.Security.Cryptography;
using System.Security.Cryptography.X509Certificates;
namespace SslTest
{
    public partial class Form1 : Form
    {
        
        private const ushort SO_SECURE = 0x2001;
        private const ushort SO_SEC_SSL = 0x2004;
        private const int _SO_SSL_VALIDATE_CERT_HOOK = 0x08;
        private const int SO_SSL_FAMILY = 0x00730000;
        private const long _SO_SSL = ((2L << 27) | SO_SSL_FAMILY);
        private const uint IOC_IN = 0x80000000;
        private const long SO_SSL_SET_VALIDATE_CERT_HOOK = (IOC_IN | _SO_SSL | _SO_SSL_VALIDATE_CERT_HOOK);
        public delegate int SSLVALIDATECERTFUNC(uint dwType, IntPtr pvArg, uint dwChainLen, IntPtr pCertChain, uint dwFlags);
        private IntPtr hookFunc;
        public Form1()
        {
            InitializeComponent();
        }
        private void btnReceive_Click(object sender, EventArgs e)
        {
            Socket socket = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.IP);
            
            socket.SetSocketOption(SocketOptionLevel.Socket, (SocketOptionName)SO_SECURE, SO_SEC_SSL);
            hookFunc = Marshal.GetFunctionPointerForDelegate(new SSLVALIDATECERTFUNC(ValidateCert));

            byte[] inBuffer = new byte[8];
            byte[] hookFuncBytes = BitConverter.GetBytes(hookFunc.ToInt32());
            Array.Copy(hookFuncBytes, inBuffer, hookFuncBytes.Length);
            unchecked
            {
                socket.IOControl((int)SO_SSL_SET_VALIDATE_CERT_HOOK, inBuffer, null);
            }
            
            IPHostEntry hostEntry = Dns.GetHostEntry("xxx.xxx.xxx.xxx");
            IPEndPoint ip = new IPEndPoint(hostEntry.AddressList[0], 995);
            socket.Connect(ip);
            NetworkStream netStream = new NetworkStream(socket);
            StreamReader reader = new StreamReader(netStream);
            MessageBox.Show(reader.ReadLine());
            netStream.Close();
            reader.Close();
            
            socket.Shutdown(SocketShutdown.Both);
            socket.Close();
        }
        private int ValidateCert(uint dwType, IntPtr pvArg, uint dwChainLen, IntPtr pCertChain, uint dwFlags)
        {
            return 0;
        }
    }
}