.NET 4.x Прием электронных сообщений, POP3, SSL/TLS - C#

using System;
using System.Text;
using System.Net.Sockets;
using System.Windows.Forms;
 
namespace Pop3
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }
 
        private void button1_Click(object sender, EventArgs e)
        {
            TcpClient tcpClient = new TcpClient();
            tcpClient.Connect("pop.mail.ru", 110);
            NetworkStream netStrm = tcpClient.GetStream();
            System.IO.StreamReader strRead = new System.IO.StreamReader(netStrm);
            if (tcpClient.Connected)
            {
                MessageBox.Show("connected: " + strRead.ReadLine());
            }
            string login = "USER\r\n";
            byte[] WriteBuffer = new byte[1024];
            ASCIIEncoding en = new System.Text.ASCIIEncoding();
            WriteBuffer = en.GetBytes(login);
            netStrm.Write(WriteBuffer, 0, WriteBuffer.Length);
            MessageBox.Show("response: " + strRead.ReadLine());
            login = "PASSWORD\r\n";
            WriteBuffer = en.GetBytes(login);
            netStrm.Write(WriteBuffer, 0, WriteBuffer.Length);
            MessageBox.Show("response: " + strRead.ReadLine());
 
            login = "LIST\r\n";
            WriteBuffer = en.GetBytes(login);
            netStrm.Write(WriteBuffer, 0, WriteBuffer.Length);
            string resp;
            while (true)
            {
                resp = strRead.ReadLine();
                MessageBox.Show("could resp be .\r\n " + resp);
                if (resp == ".")
                {
                    MessageBox.Show("yes");
                    break;
                }
                else
                {
                    MessageBox.Show("list: " + resp);
                    continue;
                }
            }
 
            login = "QUIT\r\n";
            WriteBuffer = en.GetBytes(login);
            netStrm.Write(WriteBuffer, 0, WriteBuffer.Length);
            MessageBox.Show("response: " + strRead.ReadLine());
        }
 
        private void btnConnect_Click(object sender, EventArgs e)
        {            
            TcpClient tcpClient = new TcpClient();
            txtLog.Text = "I say:\r\nConnect me to " + txtServer.Text + ":" + txtPort.Text + "\r\n\r\n";
            tcpClient.Connect(txtServer.Text, Convert.ToInt32(txtPort.Text));
            NetworkStream netStream = tcpClient.GetStream();
            System.IO.StreamReader strReader = new System.IO.StreamReader(netStream);
            if (tcpClient.Connected)
            {
                txtLog.Text += "Server says:\r\n" + strReader.ReadLine() + "\r\n\r\n";
                byte[] WriteBuffer = new byte[1024];
                ASCIIEncoding enc = new System.Text.ASCIIEncoding();
                WriteBuffer = enc.GetBytes("USER " + txtUser.Text + "\r\n");
                txtLog.Text += "I say:\r\nHere's the username: " + txtUser.Text + "\r\n\r\n";
                netStream.Write(WriteBuffer, 0, WriteBuffer.Length);
                txtLog.Text += "Server says\r\n" + strReader.ReadLine() + "\r\n\r\n";
                WriteBuffer = enc.GetBytes("PASS " + txtPass.Text + "\r\n");
                txtLog.Text += "I say:\r\nHere's the password: " + txtPass.Text + "\r\n\r\n";
                netStream.Write(WriteBuffer, 0, WriteBuffer.Length);
                txtLog.Text += "Server says:\r\n" + strReader.ReadLine() + "\r\n\r\n";
                WriteBuffer = enc.GetBytes("LIST\r\n");
                txtLog.Text += "I say:\r\nPlease list the messages\r\n\r\n";
                netStream.Write(WriteBuffer, 0, WriteBuffer.Length);
                string ListMessage;
                while (true)
                {
                    try
                    {
                        ListMessage = strReader.ReadLine();
                        if (ListMessage == ".")
                        {
                            break;
                        }
                        else
                        {
                            txtLog.Text += "Server says:\r\n" + ListMessage + "\r\n\r\n";
                            continue;
                        }
                    }
                    catch (System.IO.IOException ex)
                    {
                        MessageBox.Show(ex.Message);
                    }
                }
                txtLog.Text += "I say:\r\nThanks, we will disconnect now\r\n\r\n";
                WriteBuffer = enc.GetBytes("QUIT\r\n");
                netStream.Write(WriteBuffer, 0, WriteBuffer.Length);
                txtLog.Text += "Server says:\r\n" + strReader.ReadLine();
            }
        }
    }
}