通过163smtp服务器向各大邮箱发送邮件(SOCKET编程)

package server;

import java.io.*;
import java.net.*;
import java.sql.Time;
import java.util.Scanner;
import java.util.Timer;

public class client {

/*通过163smtp服务器向其他邮箱发送数据
* 返回码
* 0：未知原因出错
* 1：发送成功
* 2：被判定为垃圾邮件
*/
public static int send(Mail mail){
int state=0;
Socket socket=null;
String userName="xxxxxxxxx";//经过base64编码的163邮箱用户名
String password="xxxxxxxxxxxxxx";//经过base64编码的163邮箱密码
BufferedReader reader=null;
PrintWriter writer=null;
try {
// 连接到服务器
socket = new Socket("SMTP.163.com", 25);
reader = new BufferedReader(new InputStreamReader(socket.getInputStream()));
writer = new PrintWriter(socket.getOutputStream(), true);
System.out.println(reader.readLine());
writer.println("HELO 163");
System.out.println(reader.readLine());
writer.println("auth login");
System.out.println(reader.readLine());
writer.println(userName);
System.out.println(reader.readLine());
writer.println(password);
System.out.println(reader.readLine());
writer.println("mail from:<mailsys163@163.com>");
System.out.println(reader.readLine());
writer.println("rcpt to:<" +mail.getReceiver()+">");
System.out.println(reader.readLine());
//开始发送邮件
writer.println("data");
System.out.println(reader.readLine());
writer.println("subject:"+mail.getSubject());
writer.println("from:"+mail.getSender());
writer.println("to:"+mail.getReceiver());
writer.println("Content-Type: text/plain;charset=\"gb2312\"");
writer.println("");
writer.println(mail.getContent());
writer.println(".");
writer.println("");
String sum=reader.readLine();
System.out.println(sum);
if(sum.indexOf("250")==0){
System.out.println("发送成功");
state=1;
}else if(sum.indexOf("554")==0){
System.out.println("被判定为垃圾邮件");
state=2;
}
writer.println("rset");
System.out.println(reader.readLine());
writer.println("quit");
} catch (IOException e) {
e.printStackTrace();
}finally {
try {
socket.close();
reader.close();
writer.close();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
return state;
}

public static void main(String[] args){
Mail mail=new Mail("xxxxxxx@163.com","xxxxx@qq.com","你好","吃饭了没");
System.out.println(send(mail));

}
}

注意如果是163向163发送邮件，邮件的发送者（mail.sender,不是真实发送者这个必须和认证的用户名相同)可以设置为任意的，这样接收者收到邮件时会看到该邮件由认证的用户代发



但是如果是163向其他邮箱发送邮件，这两个from必须相同，否则大部分情况下都会被163当作是垃圾邮件返回554错误，无发发送