Mail client using TcpClient class

Question

I found example of receiving messages from mail box:

// create an instance of TcpClient 

            TcpClient tcpclient = new TcpClient();

            // HOST NAME POP SERVER and gmail uses port number 995 for POP 

            tcpclient.Connect("pop.gmail.com", 995);
            // This is Secure Stream // opened the connection between client and POP Server
            System.Net.Security.SslStream sslstream = new SslStream(tcpclient.GetStream());
            // authenticate as client  
            sslstream.AuthenticateAsClient("pop.gmail.com");
            //bool flag = sslstream.IsAuthenticated;   // check flag
            // Asssigned the writer to stream 
            System.IO.StreamWriter sw = new StreamWriter(sslstream);
            // Assigned reader to stream
            System.IO.StreamReader reader = new StreamReader(sslstream);
            // refer POP rfc command, there very few around 6-9 command
            sw.WriteLine("USER your_gmail_user_name@gmail.com");
            // sent to server
            sw.Flush();
            sw.WriteLine("PASS your_gmail_password");
            sw.Flush();
            // this will retrive your first email
            sw.WriteLine("RETR 1");
            sw.Flush();
            // close the connection
            sw.WriteLine("Quit ");
            sw.Flush();
            string str = string.Empty;
            string strTemp = string.Empty;
            while ((strTemp = reader.ReadLine()) != null)
            {
                // find the . character in line
                if (strTemp == ".")
                {
                    break;
                }
                if (strTemp.IndexOf("-ERR") != -1)
                {
                    break;
                }
                str += strTemp;
            }

But I don't understand how to print message body in rich text box for example. Which string contains response? Can anyone help me?

Thank you very much!

Answer 1

As I wrote in reply to your other, nearly identical, question: you really need to read the MIME specifications and the POP3 specification if you ever hope to write a mail client.

Or you could use a library which has done most of the hard work for you, such as MimeKit and MailKit.

You'll still really need to have at least a basic understanding of MIME, but at least you won't have to write a parser for it (which is non-trivial seeing as how many messages in the real world do not follow the specifications - often having been written by folks who never bothered to actually read the specifications).

Answer 2

Well from what I understand in this code, the mail should be in the str string. But I think you should read the mail before sending quit to the server. So put your loop before

        // close the connection
        sw.WriteLine("Quit ");
        sw.Flush();