>PHP: getmxrr - Manual

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getmxrr

choward AT fast DOT net DOT NO SPAM PLZ
12-Apr-2006 12:32


Below Code Used and edited from -ng4rrjanbiah at rediffmail dot com- posted note.

Testing on Windows 2000 Advanced Server.

PHP v4.4.1



function getmxrr($hostname, &$mxhosts)

{

   $mxhosts = array();

   exec('%SYSTEMDIRECTORY%\\nslookup.exe -q=mx '.$hostname, $result_arr);

   foreach($result_arr as $line) 

   {

     if (preg_match("/.*mail exchanger = (.*)/", $line, $matches)) 

         $mxhosts[] = $matches[1];

   }

   return( count($mxhosts) > 0 );

}//--End of workaround



//test..

getmxrr('yahoo.com', $mxhosts);

print_r($mxhosts);



As you can see the only thing i had to do in order to make this work was add a direct path to nslookup and add the .exe extension. You can use either the "Type" or "Q" parameter, both worked for me. I am not sure as to why the inital script failed... Safe Mode is on, but that is not the culprit. If i look into it and find an answer i will post it. My initial thoughts are that the SystmDir and WinDir Environment Vars are set to C:\WINNT when i would think SystemDir is actually supposed to be C:\WINNT\System32 for windows systems... but i also think that because C:\WINNT\System32 is in my Windows OS Environmental Var PATH that it shouldn't matter so i am not sure why i had to put in the whole path, but either way it now works. If anyone has some insight or simply wants to point me to something i can read, that'd be much appreciated as i will probably not think about this issue again... Especially since this particular system has had way too many changes to it and programs installed etc... it is an all around test unit. The issue may be mine alone, but i thought i would post this in hopes of saving someone time just in case.

Lennart Poot(www.twing.nl)
07-Apr-2006 12:23


This script validates an e-mail adress using getmxrr and fsockopen



1. it validates the syntax of the address.

2. get MX records by hostname

3. connect mail server and verify mailbox(using smtp command RCTP TO:<email>)



When the function "validate_email([email])" fails connecting the mail server with the highest priority in the MX record it will continue with the second mail server and so on..



The function "validate_email([email])" returns 0 when it failes one the 3 steps above, it will return 1 otherwise



Grtz Lennart Poot



<?

function validate_email($email){

   $mailparts=explode("@",$email);

   $hostname = $mailparts[1];



   // validate email address syntax

   $exp = "^[a-z\'0-9]+([._-][a-z\'0-9]+)*@([a-z0-9]+([._-][a-z0-9]+))+$";

   $b_valid_syntax=eregi($exp, $email);



   // get mx addresses by getmxrr

   $b_mx_avail=getmxrr( $hostname, $mx_records, $mx_weight );

   $b_server_found=0;



   if($b_valid_syntax && $b_mx_avail){

     // copy mx records and weight into array $mxs

     $mxs=array();



     for($i=0;$i<count($mx_records);$i++){

       $mxs[$mx_weight[$i]]=$mx_records[$i];

     }



     // sort array mxs to get servers with highest prio

     ksort ($mxs, SORT_NUMERIC );

     reset ($mxs);



     while (list ($mx_weight, $mx_host) = each ($mxs) ) {

       if($b_server_found == 0){



         //try connection on port 25

         $fp = @fsockopen($mx_host,25, $errno, $errstr, 2);

         if($fp){

           $ms_resp="";

           // say HELO to mailserver

           $ms_resp.=send_command($fp, "HELO microsoft.com");



           // initialize sending mail 

           $ms_resp.=send_command($fp, "MAIL FROM:<support@microsoft.com>");



           // try receipent address, will return 250 when ok..

           $rcpt_text=send_command($fp, "RCPT TO:<".$email.">");

           $ms_resp.=$rcpt_text;

           

           if(substr( $rcpt_text, 0, 3) == "250")

             $b_server_found=1;



           // quit mail server connection

           $ms_resp.=send_command($fp, "QUIT");



         fclose($fp);



         }



       }

    }

  }

  return $b_server_found;

}



function send_command($fp, $out){



  fwrite($fp, $out . "\r\n");

  return get_data($fp);

}



function get_data($fp){

  $s="";

  stream_set_timeout($fp, 2);



  for($i=0;$i<2;$i++)

    $s.=fgets($fp, 1024);



  return $s;

}



// support windows platforms

if (!function_exists ('getmxrr') ) {

  function getmxrr($hostname, &$mxhosts, &$mxweight) {

    if (!is_array ($mxhosts) ) {

      $mxhosts = array ();

    }



    if (!empty ($hostname) ) {

      $output = "";

      @exec ("nslookup.exe -type=MX $hostname.", $output);

      $imx=-1;



      foreach ($output as $line) {

        $imx++;

        $parts = "";

        if (preg_match ("/^$hostname\tMX preference = ([0-9]+), mail exchanger = (.*)$/", $line, $parts) ) {

          $mxweight[$imx] = $parts[1];

          $mxhosts[$imx] = $parts[2];

        }

      }

      return ($imx!=-1);

    }

    return false;

  }

}



?>

jeff at pzenix dot com
08-Mar-2006 09:58


I should point out that the below example won't work with some domains (.co.uk, .org.uk, .net.uk for example) because it assumes (possibly incorrectly) that the format is [ DOMAIN ].[ EXT ].

off at NOSPAM dot abwesend dot de
11-Feb-2006 07:18


Concerning the message by 'rolf at rowi dot net' (do a check on a address containing a subdomain) we could use:



$email = 'abc@etpc01.trier.fh-rpl.de';

            

$strDot      = '.';

$strAfterAt  = substr(strstr($email, '@'), 1);

$chunks      = explode($strDot, $strAfterAt);

$cntChunks   = count($chunks) - 1;



$strDomain = $chunks[($cntChunks-1)] . $strDot . $chunks[$cntChunks];



if (!getmxrr( $strDomain, $mxhosts )) {

    echo 'Mailserver not found';

}



// $strDomain is set to 'fh-rpl.de';

31-Aug-2005 08:16


nice function for validating email-adresses! Take care on "register globals" paramter.



http://www.zend.com/zend/spotlight/ev12apr.php

richard dot quadling at bandvulc dot co dot uk
25-May-2005 02:04


Windows alternative for getmxrr without the need for PEAR.



define('DEFAULT_GATEWAY', 'nnn.nnn.nnn.nnn');

function raqgetmxrr($sHostName, &$aMXHosts, &$aWeights = NULL)

    {

    /*

        This function is a replacement for the missing Windows function getmxrr.

        

        The parameters are the same as those for the normal getmxrr function.

        

        The steps this function takes are :

        

        1 - Use NSLOOKUP.EXE to get the MX records for the supplied Host.

        2 - Use regular expressions to extract the mail servers and the preference.

        3 - Sort the results by preference.

        4 - Set the return arrays.

        5 - Return true or false.

    */

    $sNSLookup = shell_exec("nslookup -q=mx {$sHostName} DEFAULT_GATEWAY 2>nul");

    preg_match_all("'^.*MX preference = (\d{1,10}), mail exchanger = (.*)$'simU", $sNSLookup, $aMXMatches);

    if (count($aMXMatches[2]) > 0)

        {

        array_multisort($aMXMatches[1], $aMXMatches[2]);

        $aMXHosts = $aMXMatches[2];

        if (!is_null($aWeights))

            {

            $aWeights = $aMXMatches[1];

            }

        return True;

        }

    else

        {

        return False;

        }

    }



You will need to know your default gateway (either it's IP address or its name).



To do this, run the program IPCONFIG /ALL at a cmd prompt and look for the Default Gateway.



Then replace the 'nnn.nnn.nnn.nnn' with the address.



Richard.

josh/endquote/com
10-Feb-2005 12:56


See this article for a validation tutorial that uses this function and more:



http://www.devshed.com/c/a/PHP/Email-Address-Verification-with-PHP/

rune dot heggtveit at devzone dot progative dot com
23-Jan-2005 01:02


An other way to do mx-lookup on a windows platform.

Rewrote this from an other class i wrote for DNS lookup - so it might be a bit messy - but hope you get the idea.



Big thanks to the rfc community.



<?php



class mxlookup

{

      var $dns_socket = NULL;

      var $QNAME = "";

      var $dns_packet= NULL;

      var $ANCOUNT = 0;

      var $cIx = 0;

      var $dns_repl_domain;

      var $arrMX = array();



      function mxlookup($domain, $dns="192.168.2.1")

      {

         $this->QNAME($domain);

         $this->pack_dns_packet();

         $dns_socket = fsockopen("udp://$dns", 53);



         fwrite($dns_socket,$this->dns_packet,strlen($this->dns_packet));

         $this->dns_reply  = fread($dns_socket,1);

         $bytes = stream_get_meta_data($dns_socket);

         $this->dns_reply .= fread($dns_socket,$bytes['unread_bytes']);

         fclose($dns_socket);

         $this->cIx=6;

         $this->ANCOUNT   = $this->gord(2);

         $this->cIx+=4;

         $this->parse_data($this->dns_repl_domain);

         $this->cIx+=7;



         for($ic=1;$ic<=$this->ANCOUNT;$ic++)

         {

           $QTYPE = ord($this->gdi($this->cIx));

           if($QTYPE!==15){print("[MX Record not returned]"); die();}

           $this->cIx+=9;

           $mxPref = ord($this->gdi($this->cIx));

           $this->parse_data($curmx);

           $this->arrMX[] = array("MX_Pref" => $mxPref, "MX" => $curmx);

           $this->cIx+=3;

         }

      }



      function parse_data(&$retval)

      {

        $arName = array();

        $byte = ord($this->gdi($this->cIx));

        while($byte!==0)

        {

          if($byte==192) //compressed

          {

            $tmpIx = $this->cIx;

            $this->cIx = ord($this->gdi($cIx));

            $tmpName = $retval;

            $this->parse_data($tmpName);

            $retval=$retval.".".$tmpName;

            $this->cIx = $tmpIx+1;

            return;

          }

          $retval="";

          $bCount = $byte;

          for($b=0;$b<$bCount;$b++)

          {

            $retval .= $this->gdi($this->cIx);

          }

          $arName[]=$retval;

         $byte = ord($this->gdi($this->cIx));

       }

       $retval=join(".",$arName);

     }



     function gdi(&$cIx,$bytes=1)

     {

       $this->cIx++;

       return(substr($this->dns_reply, $this->cIx-1, $bytes));

     }



      function QNAME($domain)

      {

        $dot_pos = 0; $temp = "";

        while($dot_pos=strpos($domain,"."))

        {

          $temp   = substr($domain,0,$dot_pos);

          $domain = substr($domain,$dot_pos+1);

          $this->QNAME .= chr(strlen($temp)).$temp;

        }

        $this->QNAME .= chr(strlen($domain)).$domain.chr(0);

      }



      function gord($ln=1)

      {

        $reply="";

        for($i=0;$i<$ln;$i++){

         $reply.=ord(substr($this->dns_reply,$this->cIx,1));

         $this->cIx++;

         }



        return $reply;

      }



      function pack_dns_packet()

      {

        $this->dns_packet = chr(0).chr(1).

                            chr(1).chr(0).

                            chr(0).chr(1).

                            chr(0).chr(0).

                            chr(0).chr(0).

                            chr(0).chr(0).

                            $this->QNAME.

                            chr(0).chr(15).

                            chr(0).chr(1);

      }



}



?>



<?php



/* Exampe of use: */

$mx = new mxlookup("php.net");



print $mx->ANCOUNT." MX Records\n";

print "Records returned for ".$mx->dns_repl_domain.":\n<pre>";

print_r($mx->arrMX);



?>



Return:



02 MX Records Records returned for php.net:



Array

(

    [0] => Array

        (

            [MX_Pref] => 15

            [MX] => smtp.osuosl.org

        )



    [1] => Array

        (

            [MX_Pref] => 5

            [MX] => osu1.php.net

        )



)

rolf at rowi dot net
21-Jan-2005 06:36


Be aware that not just user@example.com ist a valid address, also user@subnet.example.com is valid (but maybe less common). Just got into trouble with this check...



Rolf

siclawrence at gmail dot com
04-Jan-2005 06:43


This code replicates online tools that let you check if an email address is valid. First it checks if the email format is correct, then looks up and prints the mx records. All nicely formatted with fancy words that in the end prints whether the email address valid or invalid.



<?php

$email = "email@domain.com";



print("Checking: $email<br>");



if (eregi("^[_a-z0-9-]+(\.[_a-z0-9-]+)*@[a-z0-9-]+(\.[a-z0-9-]+)+$", $email)) {



    print("Format Test: PASSED<br>");

    print("Online host verification Test...<br><br>");

    print("MX Records for: $email<br>");

    

    list($alias, $domain) = split("@", $email); 

    

    if (checkdnsrr($domain, "MX")) {

    

        getmxrr($domain, $mxhosts);

        

        foreach($mxhosts as $mxKey => $mxValue){

            print("&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;$mxValue<br>");

        }

        

        print("Online host verification Test: PASSED<br><br>");

        print("Email Status: VALID");

    

    } else {

    

        print("&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;No records found.<br>");

        print("Online host verification Test: FAILED<br><br>");

        print("Email Status: INVALID");

    

    }



} else {



    print("Format Test: FAILED<br><br>");

    print("Invalid email address provided.<br><br>");

    print("Email Status: INVALID");

    

}

?>

zorlac_man at hotmail dot com
14-May-2004 12:15


For some reason this and the other DNS lookup functions seem to be really slow on my Linux box. I've checked several things and have no explanation.



As a work-around, I gave in and just used a system call to dig:



<?php

CheckMX("fakedomain.org");

CheckMX("hotmail.com");



function CheckMX($domain) {

        exec("dig +short MX " . escapeshellarg($domain),$ips);

        if($ips[0] == "") {

                print "MX record found for $domain not found!\n";

                return FALSE;

        }

        print "MX Record for $domain found\n";

        return TRUE;

}

?>



Output:



MX record found for fakedomain.org not found!

MX Record for hotmail.com found



As someone else pointed out, it is prudent to check to see if the TLD has an IP address if the MX record is not found.

ng4rrjanbiah at rediffmail dot com
26-Feb-2004 03:11


Here is a better workaround for Windows platform. Tested on Windows XP. Highly impressed by "geoffbrisbine A T y a h o o DOT c o m"'s idea of nslookup usage.



<?php

function getmxrr($hostname, &$mxhosts)

{

   $mxhosts = array();

   exec('nslookup -type=mx '.$hostname, $result_arr);

   foreach($result_arr as $line) 

    {

      if (preg_match("/.*mail exchanger = (.*)/", $line, $matches)) 

          $mxhosts[] = $matches[1];

    }

   return( count($mxhosts) > 0 );

}//--End of workaround



//test..

echo getmxrr('yahoo.com', $mxhosts);

print_r($mxhosts);

?>



HTH,

R. Rajesh Jeba Anbiah

geoffbrisbine A T y a h o o DOT c o m
24-Sep-2002 09:39


I was pretty disappointed that the Win32 build of PHP doesn't incorporate getmxrr so, since I'm a naive newbie, I decided to hack together my own (and I stress hack).  This has been tested on Win 2000 and Win XP.  There's no reason this shouldn't work on Win NT but it will not work on Win 9x (you need the nslookup command).  It will finish with the array $mx that will be a multidimensional array with the MX preference, host name and ip address. You can do a print_r ( $mx ) to see what it looks like.



-----------------------------------------------



<?php

$command = "nslookup -type=mx yahoo.com";

exec ( $command, $result );

    

$i = 0;

while ( list ( $key, $value ) = each ( $result ) ) {

    if ( strstr ( $value, "mail exchanger" ) ) { $nslookup[$i] = $value; $i++; }

}

    

while ( list ( $key, $value ) = each ( $nslookup ) ) {

    $temp = explode ( " ", $value );

    $mx[$key][0] = $temp[3];

    $mx[$key][1] = $temp[7];

    $mx[$key][2] = gethostbyname ( $temp[7] );

}



    array_multisort ( $mx );

?>

paul at start dot co dot uk
16-Jan-2001 12:48


Prevent your dns server from 'creating' a valid host name by appending the local domain to incomplete emails by appending to the domain a  trailing . both in the pattern match and mx checks:





if (eregi("^[0-9a-z_]([-_.]?[0-9a-z])*@[0-9a-z][-.0-9a-z]*\\.[a-z]{2,3}[.]?$", $string, $check)) { 


    $host = substr(strstr($check[0], '@'), 1)."."; 


    if ( getmxrr($host, $validate_email_temp) ) 


        return TRUE; 


    // THIS WILL CATCH DNSs THAT ARE NOT MX. 


    if(checkdnsrr($host,"ANY"))


        return TRUE; 


} 


return FALSE;

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getmxrr

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