Reputation: 16910
I was reading C# 4.0 in a Nutshell by Joseph and Ben Albahari and came across this code in Networking chapter which reads the mails using POP3. POP3 has a defined communication as we all know. When I use the code in the chapter it looks obvious that it should work but it doesn't. This is the code:
private static string ReadLine(Stream stream)
{
List<byte> list = new List<byte>();
while (true)
{
int b = stream.ReadByte();
if (b == 10 || b < 0) break;
if (b != 13) list.Add( (byte)b);
}
return Encoding.UTF8.GetString(list.ToArray());
}
private static void SendCommand(Stream stream, string line)
{
byte[] byteArr = Encoding.UTF8.GetBytes(line + "\r\n");
stream.Write(byteArr, 0, byteArr.Length);
string response = ReadLine(stream);
if (!response.StartsWith("+OK"))
throw new Exception("Pop exception: " + response);
}
static void Main(string[] args)
{
using (TcpClient client = new TcpClient("pop.gmail.com", 995))
{
using (NetworkStream stream = client.GetStream())
{
ReadLine(stream);
}
}
The code is incomplete in the sense that it doesn't download mails. I was just trying to see what is the 1st reponse that we get from Gmail. But unfortunately, the program just stucks at ReadByte
in ReadLine
method. I think I should get this line when I first connect to the gmail:
+OK Hello there.
But my program just hangs. As per this page:
http://mail.google.com/support/bin/answer.py?answer=13287
you have to connect on pop.gmail.com which is exactly what I have done. Can anybody tell me what is missing?
Note: Do not send me any 3rd party projects to do this sort of this. I know it is very easy using them. But I am just trying to see what happens under the hoods. It would be better for me if you find the bug present in my program itself.
Thanks.
Upvotes: 1
Views: 1289
Reputation: 4253
Use SslStream
instead of NetworkStream
as gmail requires ssl
TcpClient objTcpClient = new TcpClient();
//Connecting to the pop3 server at the specified port
objTcpClient.Connect(pop3Server, pop3PortNumber);
//ValidateCertificate is a delegate
SslStream netStream = new SslStream(objTcpClient.GetStream(), false, ValidateCertificate); //Authenticates the client on the server
netStream.AuthenticateAsClient(pop3Server);
//Stream Reader to read response stream
StreamReader netStreamReader = new StreamReader(netStream, Encoding.UTF8, true);
Upvotes: 2
Reputation: 6391
Gmail requires you to use SSL.
995 port is POP3 over SSL, consider using SslStream.
Upvotes: 1