Java E-mail Sender

COMP211 Tutorials 2021-10-07

In order to establish a TCP connection and send commands to a server you can use the following skeleton code:

import java.io.*;
import java.net.*;

public class EmailSender
{
	public static void main(String[] args) throws Exception
	{
		// Establish a TCP connection with the mail server.
		Socket socket = new Socket("35.246.112.180",1025);

		// Create a BufferedReader to read a line at a time.
		InputStream is = socket.getInputStream();
		InputStreamReader isr = new InputStreamReader(is);
		BufferedReader br = new BufferedReader(isr);

		// Read greeting from the server.
		String response = br.readLine();
		System.out.println(response);
		if (!response.startsWith("220")) {
		 throw new Exception("220 reply not received from server.");
		}

		// Get a reference to the socket's output stream.
		DataOutputStream os = new DataOutputStream(socket.getOutputStream());

		// Send HELO command and get server response.
		String command = "HELO alice\r\n";
		System.out.print(command);
		os.writeBytes(command);
		response = br.readLine();
		System.out.println(response);
		if (!response.startsWith("250")) {
		 throw new Exception("250 reply not received from server.");
		}
	}
}