moudey

/// <summary>
/// RFC1939 - Post Office Protocol - Version 3 (POP3)
/// <seealso cref="http://www.faqs.org/rfcs/rfc1939" />
/// </summary>
class POP3
{
    Stream        stream        = null;
    TcpClient    tcpclient    = new TcpClient();
    bool        connected    = false;
    bool        isLogedon    = false;
 
    public bool Connected
    {
        get { return connected; }
    }
 
    public bool IsLogedon
    {
        get { return isLogedon; }
    }
 
    public POP3(string host, int port, bool ssl)
    {
        try {
            // open port 110 ( the pop3 port ) On the server 
            // catch any error resuting from a bad server name 
            tcpclient.Connect(host, port);    // default port 110
            if(tcpclient.Connected) {
                if(true == ssl) {
                    // This is Secure Stream 
                    // opened the connection between client and POP Server
                    SslStream sslstream = new SslStream(tcpclient.GetStream());
                    // authenticate as client 
                    sslstream.AuthenticateAsClient(host);
                    //bool flag = sslstream.IsAuthenticated; // check flag 
                    stream = sslstream;
                } else {
                    // opened the connection between client and POP Server
                    stream = tcpclient.GetStream();
                }
                // check that the connection is okay 
                if(getData().StartsWith("+OK"))
                    connected = true;
            }
        } catch {
        }
    }
 
    string getData()
    {
        if(!tcpclient.Connected)
            return string.Empty;
        byte[] data = new byte[tcpclient.ReceiveBufferSize];
        // get the response 
        stream.Read(data, 0, data.Length);
        // return the response 
        return System.Text.Encoding.Default.GetString(data);
    }
 
    public string SendCmd(string cmd)
    {
        if(!connected)
            return string.Empty;
        byte[] byteCMD = null;
        // byte encode the command 
        byteCMD = System.Text.Encoding.ASCII.GetBytes(cmd + "\r\n");
        // send the data
        stream.Write(byteCMD, 0, byteCMD.Length);
        return getData();
    }
 
    public bool Logon(string user, string pass)
    {
        string ret = string.Empty; ;
        // make sure you have a connection 
        if(connected) {
            // refer POP rfc command, there very few around 6-9 command
            //send the username 
            ret = SendCmd("USER " + user);
            //if that was successfull, send the password 
            if(ret.StartsWith("+OK")) {
                ret = SendCmd("PASS " + pass);
                //if that was successfull set the return flas to true 
                if(ret.StartsWith("+OK")) {
                    return (isLogedon = true);
                }
            }
        }
        return false;
    }
 
    public string Logoff()
    {
        // close the connection
        isLogedon = false;
        return (connected ? SendCmd("QUIT") : string.Empty);
    }
}