php验证信箱是否真实存在

php验证邮箱是否真实存在
大家好，我是php新手，现在有个问题想请教大家，就是注册时验证该email地址是否真的存在，谢谢

环境win32+php5.45

test.php

echo "
检查电子邮件地址的正确性:
"; 
require("email_validation.php"); 
$newmail = "[email protected]"; 
$validator=new email_validation_class; 
$validator->timeout=10; 

//if(IsSet($newemail) && strcmp($newemail,"")){
	if( ($result=$validator->ValidateEmailBox($newmail) )		echo "不能确定您的信箱是否正确. 您的信箱离这里太远了吧?
"; 
		return; 
	}else{ 
			echo "22222222";
		if(!$result){ 
			echo "您输入的信箱地址是不正确的! :)
"; 
			return; 
		}else{
			echo "邮箱合法!
"; 
		} 
	}

?>

 
class email_validation_class 
{ 
//var $email_regular_expression="^([a-z0-9_] |//- |//.)+@(([a-z0-9_] |//-)+//.)+[a-z]{2,4}$"; 
var $timeout=0; 
var $localhost=""; 
var $localuser=""; 
var $hosts=0;

Function GetLine($connection) 
{ 
for($line="";;) 
{ 
if(feof($connection)) 
return(0); 
$line.=fgets($connection,100); 
$length=strlen($line); 
if($length>=2 && substr($line,$length-2,2)=="/r/n") 
return(substr($line,0,$length-2)); 
} 
} 

Function PutLine($connection,$line) 
{ 
return(fputs($connection,"$line/r/n")); 
} 

Function ValidateEmailAddress($email) { 
//return(eregi($this->email_regular_expression,$email)!=0); 
//origin:
//return(eregi("^([a-z0-9_] |//- |//.)+@(([a-z0-9_] |//-)+//.)+[a-z]{2,4}$",$email)!=0); 

//return preg_match("/^[_a-z0-9-]+(\.[_a-z0-9-]+)*@[a-z0-9-]+(\.[a-z0-9-]+)*(\.[a-z]{2,3})$/i", $_REQUEST[$email]);
return preg_match("/^[_a-z0-9-]+(\.[_a-z0-9-]+)*@[a-z0-9-]+(\.[a-z0-9-]+)*(\.[a-z]{2,3})$/", $_REQUEST[$email]);

} 

Function ValidateEmailHost($email,$hosts=0) 
{ 
if(!$this->ValidateEmailAddress($email)) 
return(0); 
$user=strtok($email,"@"); 
$domain=strtok(""); 
if(GetMXRR($domain,$hosts,$weights)) 
{ 
$mxhosts=array(); 
for($host=0;$host$mxhosts[$weights[$host]]=$hosts[$host]; 
KSort($mxhosts); 
for(Reset($mxhosts),$host=0;$host$hosts[$host]=$mxhosts[Key($mxhosts)]; 
} 
else 
{ 
$hosts=array(); 
if(strcmp(@gethostbyname($domain),$domain)!=0) 
$hosts[]=$domain; 
} 
return(count($hosts)!=0); 
} 

Function VerifyResultLines($connection,$code) 
{ 
while(($line=$this->GetLine($connection))) 
{ 
if(!strcmp(strtok($line," "),$code)) 
return(1); 
if(strcmp(strtok($line,"-"),$code)) 
return(0); 
} 
return(-1); 
} 

Function ValidateEmailBox($email) 
{ 
if(!$this->ValidateEmailHost($email,$hosts)) 
return(0); 
if(!strcmp($localhost=$this->localhost,"") && !strcmp($localhost=getenv("SERVER_NAME"),"") && !strcmp($localhost=getenv("HOST"),"")) 
$localhost="localhost"; 
if(!strcmp($localuser=$this->localuser,"") && !strcmp($localuser=getenv("USERNAME"),"") && !strcmp($localuser=getenv("USER"),"")) 
$localuser="root"; 
for($host=0;$host{ 
if(($connection=($this->timeout ? fsockopen($hosts[$host],25,$errno,$error,$this->timeout) : fsockopen($hosts[$host],25)))) 
{ 
if($this->VerifyResultLines($connection,"220")>0 && $this->PutLine($connection,"HELO $localhost") && $this->VerifyResultLines($connection,"250")>0 && $this->PutLine($connection,"MAIL FROM: ") && $this->VerifyResultLines($connection,"250")>0 && $this->PutLine($connection,"RCPT TO: ") && ($result=$this->VerifyResultLines($connection,"250"))>=0) 
{ 
fclose($connection); 
return($result); 
} 
fclose($connection); 
} 
} 
return(-1); 
} 
}; 

?>