+$data_email_fn = 'bulk_of_emails.csv';

+$email_from = 'sender@example.com';

+

+include_once("helper.php");

+

+// $data_email_fn = 'btpn-3-rev-part1.csv';

+$data_email_fn = 'btpn-3-rev-part2.csv';

+$email_from = 'boomeeco@gmail.com';

+

+$mailhost_cache = array();

+

+// result

+$email_valid = array();

+$email_not_valid = array();

+$row = 1;

+if( ($fh = fopen($data_email_fn, "r")) !== FALSE ){

+  while( ($row = fgetcsv($fh, 1000, ",")) !== FALSE ){

+    $email = (!empty($row[0]) ? trim($row[0]) : null);

+    

+    $mailhost = substr($email, strpos($email, '@'));

+    $mailhost = str_replace('@', '', $mailhost);

+

+    // debug-test-invalid

+    // $email = 'bijikudakejepit@gmail.com';

+    

+    clog(' > '.$email, !1);

+    $resp = verifyEmail($email, $email_from, true);

+    

+    if( !empty($resp) && $resp[0] == 'valid' ){

+      clog(" [Ok]");

+      $email_valid[] = $email;

+    }

+    else{

+      

+      clog(" [-INVALID-]");

+      $email_not_valid[] = $email;

+    }

+  }

+

+  echo "VALID-EMAIL:";

+  print_r($email_valid);

+  echo "NOT-VALID:";

+  print_r($email_not_valid);

+}

+

+

+function clog($x, $nl=true){

+

+  echo $x.($nl ? "\n" : "");

+

+function verifyEmail($toemail, $fromemail, $getdetails = false){

+  $email_arr = explode("@", $toemail);

+  $domain = array_slice($email_arr, -1);

+  $domain = $domain[0];

+

+  // Trim [ and ] from beginning and end of domain string, respectively

+  $domain = ltrim($domain, "[");

+  $domain = rtrim($domain, "]");

+

+  $result = $details = '';

+

+  if( "IPv6:" == substr($domain, 0, strlen("IPv6:")) ) {

+    $domain = substr($domain, strlen("IPv6") + 1);

+  }

+

+  $mxhosts = array();

+  if( filter_var($domain, FILTER_VALIDATE_IP) )

+    $mx_ip = $domain;

+  else

+    getmxrr($domain, $mxhosts, $mxweight);

+

+  if(!empty($mxhosts) )

+    $mx_ip = $mxhosts[array_search(min($mxweight), $mxhosts)];

+  else {

+    if( filter_var($domain, FILTER_VALIDATE_IP, FILTER_FLAG_IPV4) ) {

+      $record_a = dns_get_record($domain, DNS_A);

+    }

+    elseif( filter_var($domain, FILTER_VALIDATE_IP, FILTER_FLAG_IPV6) ) {

+      $record_a = dns_get_record($domain, DNS_AAAA);

+    }

+

+    if( !empty($record_a) )

+      $mx_ip = $record_a[0]['ip'];

+    else {

+

+      $result   = "invalid";

+      $details .= "No suitable MX records found.";

+

+      return ( (true == $getdetails) ? array($result, $details) : $result );

+    }

+  }

+  

+  $connect = @fsockopen($mx_ip, 25); 

+  if($connect){ 

+    if(preg_match("/^220/i", $out = fgets($connect, 1024))){

+      fputs ($connect , "HELO $mx_ip\r\n"); 

+      $out = fgets ($connect, 1024);

+      $details .= $out."\n";

+ 

+      fputs ($connect , "MAIL FROM: <$fromemail>\r\n"); 

+      $from = fgets ($connect, 1024); 

+      $details .= $from."\n";

+

+      fputs ($connect , "RCPT TO: <$toemail>\r\n"); 

+      $to = fgets ($connect, 1024);

+      $details .= $to."\n";

+

+      fputs ($connect , "QUIT"); 

+      fclose($connect);

+

+      if(!preg_match("/^250/i", $from) || !preg_match("/^250/i", $to)){

+        $result = "invalid"; 

+      }

+      else{

+        $result = "valid";

+      }

+    } 

+  }

+  else{

+    $result = "invalid";

+    $details .= "Could not connect to server";

+  }

+  if($getdetails){

+    return array($result, $details);

+  }

+  else{

+    return $result;

+  }