View source for Check if an email address contains a domain with a record of spamming

Use trigger code to check whether the domain in an email address is found in [https://www.spamhaus.org/zen/ zen.spamhaus.org]'s list of blacklisted domains. If found in the blacklist, then use [https://wiki.processmaker.com/3.1/ProcessMaker_Functions#PMFRedirectToStep.28.29 PMFRedirectToStep()] to redirect back to the Dynaform, and tell the user to enter a different email address.


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'''Process:'''  [https://www.pmusers.com/media/blacklist/Check_email_for_spam_blacklist-1.pmx Check_email_for_spam_blacklist-1.pmx] (''right click'' and select '''Save link as''')<br>
'''Author:'''    Amos Batto (amos@processmaker.com)<br>
'''Version:'''   1.0 (2018-09-03)<br>
'''Tested in:''' ProcessMaker 3.2.2 Enterprise in Debian 8.4 with Firefox 51  
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Create the following DynaForm, which has a text field associated with the "email" variable:

https://www.pmusers.com/media/blacklist/emailFieldInDesigner.png

Then create the following trigger which checks if the domain of the entered email address is found in zen.spamhaus.org's blacklist: 
<source lang=javascript>
//set to the ID of the dynaform containing the "email" field:
$dynaformId = '6862687465b64de53f32e86007678473'; 
//to test set @@email to "nobody@112.198.83.17"

if (@@email) {
   $g = new G();
   
   if (preg_match('/@([a-zA-Z0-9\-_.]+)/', @@email, $aMatches) == 0) {
      $g->sendMessageText(@@email.' does not contain a valid domain. ". 
          "Enter another email address.', 'WARNING');
      PMFRedirectToStep(@@APPLICATION, @%INDEX, 'DYNAFORM', $dynaformId);
   }
   
   $ip = $domain = $aMatches[1];
   
   //if the domain is not an IP address, then lookup the IP address for the domain
   if (preg_match('/^(\d{1,3}\.){3,5}\d{1,3}$/', $domain) == 0) {
      $ip = gethostbyname($domain);
      
      if ($ip == $domain) {
         $g->sendMessageText("Cannot find IP for domain '$domain'. ".
            "Enter another email address.", 'WARNING');
         PMFRedirectToStep(@@APPLICATION, @%INDEX, 'DYNAFORM', $dynaformId);
      }
   }
   
    $blacklist = 'zen.spamhaus.org';
    $reversedIp = implode(".", array_reverse(explode(".", $ip)));
    
   //The following code doesn't work if needing to specify an alternative DNS:
   /*
   $aRecords = dns_get_record($reversedIp .'.'. $blacklist);
   if (!empty($aRecords)) { 
        $g->sendMessageText("The domain '$domain' has a record of sending spam. ".
                  "Enter another email address.", 'WARNING');
      PMFRedirectToStep(@@APPLICATION, @%INDEX, 'DYNAFORM', $dynaformId);
   } 
   */
   
   //use the "dig" command instead of dns_get_record(), but only works in Linux:
    $dns = '10.100.1.2'; //set to your DNS server
   $cmd = "dig +short $reversedIp.$blacklist @".$dns;
   @@feedback = exec($cmd); 
   
   if (@@feedback and trim(@@feedback) != '') {
      $g->sendMessageText("The domain '$domain' has a record of sending spam. ".
                  "Enter another email address.", 'WARNING');
      PMFRedirectToStep(@@APPLICATION, @%INDEX, 'DYNAFORM', $dynaformId);
   }
}
</source>
This trigger code will work if ProcessMaker is installed in a server running Linux. If using Windows or not needing to use an alternative DNS, then uncomment the code which uses the [http://php.net/manual/en/function.dns-get-record.php dns_get_record()] function to lookup the domain in spamhaus.org's blacklist.

This code will redirect the user back to the Dynaform and display a warning message to the user if an email address is entered which comes from an invalid domain or it is found in spamhaus.org's blacklist:
 
https://www.pmusers.com/media/blacklist/WarningSpammingDomain.png