要用到commons-net-3.3.jar、dnsjava-2.1.7.jar包

大部分的国内常见邮箱都能准确验证。

验证频率和数量多的话容易被封掉ip

package com.tieniu;

import java.io.IOException;

import org.apache.commons.net.smtp.SMTPClient;

import org.apache.commons.net.smtp.SMTPReply;

import org.xbill.DNS.Lookup;

import org.xbill.DNS.MXRecord;

import org.xbill.DNS.Record;

import org.xbill.DNS.Type;

public class CheckEmail {

public static final String SENDER_EMAIL = "no-reply@domain.com";//"no-reply@domain.com";

public static final String SENDER_EMAIL_SERVER = SENDER_EMAIL.split("@")[1];//"domain.com";

/**

*

* @param email The recipient's email address, it need to be validate if it is real exists or doesn't exists.

* @return True if email is real exists, false if not.

*/

public boolean checkEmailMethod(String email) {

if (!email.matches("[\\w\\.\\-]+@([\\w\\-]+\\.)+[\\w\\-]+")) {

System.err.println("Format error");

return false;

}

String log = "";

String host = "";

String hostName = email.split("@")[1];

Record[] result = null;

SMTPClient client = new SMTPClient();

client.setConnectTimeout(8000); //设置连接超时时间,有些服务器比较慢

try {

// 查找MX记录

Lookup lookup = new Lookup(hostName, Type.MX);

lookup.run();

if (lookup.getResult() != Lookup.SUCCESSFUL) {

log += "找不到MX记录\n";

return false;

} else {

result = lookup.getAnswers();

}

/*

if(result.length > 1) { // 优先级排序

List arrRecords = new ArrayList();

Collections.addAll(arrRecords, result);

Collections.sort(arrRecords, new Comparator() {

public int compare(Record o1, Record o2) {

return new CompareToBuilder().append(((MXRecord)o1).getPriority(), ((MXRecord)o2).getPriority()).toComparison();

}

});

host = ((MXRecord)arrRecords.get(0)).getTarget().toString();

}

*

*/

// 连接到邮箱服务器

for (int i = 0; i < result.length; i++) {

System.out.println(result[i].getAdditionalName().toString());

System.out.println(((MXRecord)result[i]).getPriority());

}

int count=0;

//String tempLog ="";

for (int i = 0; i < result.length; i++) {

log="";

host = result[i].getAdditionalName().toString();

try{

client.connect(host);//连接到接收邮箱地址的邮箱服务器

}catch(Exception e){//捕捉连接超时的抛出的异常

count++;

if(count>=result.length){//如果由MX得到的result服务器都连接不上，则认定email无效

log +="Connect mail server timeout...\n";

return false;

}

}

if (!SMTPReply.isPositiveCompletion(client.getReplyCode())) {//服务器通信不成功

client.disconnect();

continue;

} else {

log += "MX record about " + hostName + " exists.\n";

log += "Connection succeeded to " + host + "\n";

log += client.getReplyString();

// HELO //domain.com

try{

client.login(SENDER_EMAIL_SERVER); //这一步可能会出现空指针异常

}catch(Exception e){

return false;

}

log += ">HELO "+SENDER_EMAIL_SERVER+"\n";

log += "=" + client.getReplyString();

client.setSender(SENDER_EMAIL);

if(client.getReplyCode()!=250){//为解决hotmail有的MX可能出现=550 OU-001 (SNT004-MC1F43) Unfortunately, messages from 116.246.2.245 weren't sent.

client.disconnect();

continue;//把client.login 和client.setSender放在循环体内，这样所有的如果某mx不行就换其他mx，但这样会对无效的邮箱进行所有mx遍历，耗时

}

log += ">MAIL FROM: \n";

log += "=" + client.getReplyString();

// RCPT TO:

try{

client.addRecipient(email);

}catch(Exception e){

return false;

}

log += ">RCPT TO: \n";

log += "=" + client.getReplyString();

//最后从收件邮箱服务器返回true，说明服务器中能够找到此收件地址，邮箱有效

if (250 == client.getReplyCode()) {

return true;

}

client.disconnect();

}

}

//log+=tempLog;

//log += ">MAIL FROM: \n";

//log += "=" + client.getReplyString();

//

RCPT TO:

//try{

//client.addRecipient(email);

//}catch(Exception e){

//return false;

//}

//log += ">RCPT TO: \n";

//log += "=" + client.getReplyString();

//

最后从收件邮箱服务器返回true，说明服务器中能够找到此收件地址，邮箱有效

//if (250 == client.getReplyCode()) {

//return true;

//}

} catch (Exception e) {

e.printStackTrace();

} finally {

try {

client.disconnect();

} catch (IOException e) {

}

// print log

System.out.println(log);

}

return false;

}

/**

* This method is more accurate than checkEmailMethod(String email);

*

* @param email The recipient's email address, it need to be validate if it is real exists or doesn't exists.

* @return True if email is real exists, false if not.

*/

public boolean checkEmail(String email){

if(email.split("@")[1].equals("qq.com")){

if( checkEmailMethod(email) && checkEmailMethod(email) && checkEmailMethod(email)){

return true;

}else{

return false;

}

}

return checkEmailMethod(email);

}

public static void main(String[] args) {

CheckEmail ce = new CheckEmail();

if(ce.checkEmail("dfdegcex@qq.com")){

System.out.println("true");

}else{

System.out.println("false");

}

}

}

其中还写了一点开发过程中的相关文档，生成了该功能相应的jar包。也生成了dll，写了供C#调用的使用方法。很简单。

这里附上附件的链接：http://pan.baidu.com/s/1jHpdDjC 密码：wio6