Reading a POP3 server with only TcpClient and StreamWriter/StreamReader

问题

I'm trying to read mails from my live.com account, via the POP3 protocol.

I've found the the server is pop3.live.com and the port if 995.

I'm not planning on using a pre-made library, I'm using NetworkStream and StreamReader/StreamWriter for the job. I need to figure this out. So, any of the answers given here: Reading Email using Pop3 in C# are not usefull.

It's part of a larger program, but I made a small test to see if it works. Eitherway, i'm not getting anything. Here's the code I'm using, which I think should be correct.

EDIT: this code is old, please refer to the second block problem solved.

public Program() {
    string temp = "";
    using(TcpClient tc = new TcpClient(new IPEndPoint(IPAddress.Parse("127.0.0.1"),8000))) {
        tc.Connect("pop3.live.com",995);
        using(NetworkStream nws = tc.GetStream()) {
            using(StreamReader sr = new StreamReader(nws)) {
                using(StreamWriter sw = new StreamWriter(nws)) {
                    sw.WriteLine("USER " + user);
                    sw.Flush();
                    sw.WriteLine("PASS " + pass);
                    sw.Flush();
                    sw.WriteLine("LIST");
                    sw.Flush();
                    while(temp != ".") {
                        temp += sr.ReadLine();
                    }
                }
            }
        }
    }
    Console.WriteLine(temp);
}

Visual Studio debugger constantly falls over tc.Connect("pop3.live.com",995); Which throws an "A socket operation was attempted to an unreachable network 65.55.172.253:995" error.

So, I'm sending from port 8000 on my machine to port 995, the hotmail pop3 port. And I'm getting nothing, and I'm out of ideas.

Second block: Problem was apparently that I didn't write the quit command.

The Code:

public Program() {
    string str = string.Empty;
    string strTemp = string.Empty;
    using(TcpClient tc = new TcpClient()) {
        tc.Connect("pop3.live.com",995);
        using(SslStream sl = new SslStream(tc.GetStream())) {
            sl.AuthenticateAsClient("pop3.live.com"); 
            using(StreamReader sr = new StreamReader(sl)) {
                using(StreamWriter sw = new StreamWriter(sl)) {
                    sw.WriteLine("USER " + user);
                    sw.Flush();
                    sw.WriteLine("PASS " + pass);
                    sw.Flush();
                    sw.WriteLine("LIST");
                    sw.Flush();
                    sw.WriteLine("QUIT ");
                    sw.Flush();

                    while((strTemp = sr.ReadLine()) != null) {
                        if(strTemp == "." || strTemp.IndexOf("-ERR") != -1) {
                            break;
                        }
                        str += strTemp;
                    }
                }
            }
        }
    }
    Console.WriteLine(str);
}

回答1:

What happens if you view the Network Traffic using Wireshark? Is it sending anything at all?

Edit: I can't connect via telnet to pop3.live.com at that port either. Have you managed to successfully connect via a pop3 email client ever?

来源：https://stackoverflow.com/questions/2440151/reading-a-pop3-server-with-only-tcpclient-and-streamwriter-streamreader

标签

pop3