1.要想遠端登入QQ必須做如下處理：參考如下：

通過以上文章可以實現用telnet工具命令列發qq郵件。

2.如果telnet命令不可識別：以下是win10安裝telnet方法參考如下：

3.java實現：

package com.cl.socket2_12;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.io.PrintWriter;
import java.net.Inet4Address;
import java.net.Socket;
import java.net.UnknownHostException;
import java.text.MessageFormat;

public class MailSender {
	private String smtpServer="smtp.qq.com";//SMTP郵件伺服器的主機名
	private int port=25;
	
	public static void main(String[] args) throws UnknownHostException, IOException {
		Message msg=new Message("
 
[email protected]",   //發件地址
				"[email protected]",                   //收件方
				"hello",                                //主題
				"hi,I miss yuo very much.");             //內容
		new MailSender().sendMail(msg);
	}

	private void sendMail(Message msg) {
		Socket socket = null;
		try{
			socket=new Socket(smtpServer,port);
			BufferedReader br=getReader(socket);          //從伺服器讀
			PrintWriter pw=getWriter(socket);             //寫入aocket
			String localhost=Inet4Address.getLocalHost().getHostName();    //本地主機名
			
			//郵箱登入賬號和密碼，編碼
			String userID="
 
[email protected]";             
			String pass="fbhcgilkeiapijge";
			userID=new sun.misc.BASE64Encoder().encode(userID.getBytes());
			pass=new sun.misc.BASE64Encoder().encode(pass.getBytes());
			sendAndReceive(null,br,pw);
			//qq郵箱伺服器通訊過程：客戶端傳送的“”通過pw寫出
			sendAndReceive("HELO "+localhost,br,pw);   
			//qq郵箱伺服器特有的使用者驗證過程
			sendAndReceive("STARTTLS auth login",br ,pw);
			sendAndReceive("auth login",br,pw);
			sendAndReceive(userID, br, pw);
			sendAndReceive(pass, br, pw);
			sendAndReceive("MAIL FROM:"+msg.from,br,pw);
			sendAndReceive("RCPT TO:"+msg.to,br,pw);
			sendAndReceive("DATA",br,pw);
			pw.println(msg.data);
			System.out.println("Cliet>"+msg.data);
			sendAndReceive(".",br,pw);
			sendAndReceive("QUIT",br,pw);
		}catch (Exception e) {
			e.printStackTrace();
		}finally{
			if(socket!=null){
				try {
					socket.close();
				} catch (IOException e) {
					// TODO Auto-generated catch block
					e.printStackTrace();
				}
			}
		}
		
	}
	/**
	 * 
	 * @param str：客戶端傳送資訊
	 * @param br：讀取伺服器的響應訊息流
	 * @param pw：傳送到伺服器的流
	 * @throws IOException
	 */
	private void sendAndReceive(String str, BufferedReader br, PrintWriter pw) throws IOException {
		
		if(str!=null){
			System.out.println("Client>"+str);
			pw.println(str);
		}
		String response;
		if((response=br.readLine())!=null){
			System.out.println("Server>"+response);
		}
	}

	private BufferedReader getReader(Socket scoket) throws IOException{
		InputStream in=scoket.getInputStream();
		return new BufferedReader(new InputStreamReader(in));
	}
	private PrintWriter getWriter(Socket socket) throws IOException{
		OutputStream out=socket.getOutputStream();
		return new PrintWriter(out,true);
	}
	
}

class Message{
	String from;
	String to;
	String subject;
	String content;
	String data;
	public Message(String from, String to, String subject, String content) {
		super();
		this.from = from;
		this.to = to;
		this.subject = subject;
		this.content = content;
		this.data="Subject:"+subject+"\r\n"+content;
	}
}
 

4.以下是結果：