<![CDATA[<?php
/*
Originally
By: Jon S. Stevens jon@clearink.com
Copyright 1998 Jon S. Stevens, Clear Ink
This code has all the normal disclaimers.
It is free for any use, just keep the credits intact.
Enacements and modifications:
By: Shane Y. Gibson shane@tuna.org
Organization: The Unix Network Archives (http://www.tuna.org./)
Date: November 16th, 1998
Changes: Added **all** comments, as original code lacked them.
Added some return codes to include a bit more description
for useability.
By: Frank Vogel vogel@simec.com
Organization: Simec Corp. (http://www.simec.com)
Date: June 13th, 2000
Changes: Check for MX records for each qualification step of the domain name
Use nobdy@$SERVER_NAME as MAIL FROM: argument
I disclaim nothing...nor do I claim anything...but
it would be nice if you included this disclaimer...
*/
/* This function takes in an email address (say 'shane@tuna.org'
* and tests to see if it's a valid email address.
*
* An array with the results is passed back to the caller.
*
* Possible result codes for the array items are:
*
* Item 0: [true|false] true for valid email address
* false for NON-valid email address
*
* Item 1: [SMTP Code] if a valid MX mail server found, then
* fill this array in with failed SMTP
* reply codes
*
* Item 2: [true|false] true for valid mail server found for
* host/domain
* false if no valid mail server found
*
* Item 3: [MX server] if a valid MX host was found and
* connected to then fill in this item
* with the MX server hostname
*
* EXAMPLE code for use is at the very end of this function.
*/
function validateEmail ( $email )
{
// used for SMTP HELO argument
global $SERVER_NAME;
// initialize the return values as if no MX record appears for the specified domain
$return[0] = false;
$return[1] = "Invalid email address (bad domain name)";
$return[2] = false;
$return[3] = "";
// assign our user part and domain parts respectively to seperate
// variables
list ( $user, $domain ) = split ( "@", $email, 2 );
// split up the domain name into sub-parts
$arr = explode ( ".", $domain );
// figure out how many parts to the host/domain name portion there are
$count = count ( $arr );
// flag to indicate success
$bSuccess = false;
// we try this for each qualification step of domain name
// (from full qualified to TopLevel)
for ( $i = 0; $i < $count - 1 && !$bSuccess; $i = $i + 1 )
{
// create the domain name
$domain = "";
for ( $j = $i; $j < $count; $j = $j + 1 )
{
$domain = $domain . $arr[$j];
if ( $j < $count - 1 )
$domain = $domain . ".";
}
// check that an MX record exists for Top-Level Domain, and if so
// start our email address checking
if ( checkdnsrr ( $domain, "MX" ) )
{
// Okay...valid dns reverse record; test that MX record for
// host exists, and then fill the 'mxhosts' and 'weight'
// arrays with the correct information
if ( getmxrr ( $domain, $mxhosts, $weight ) )
{
// sift through the 'mxhosts' connecting to each host
for ( $i = 0; $i < count ( $mxhosts ); $i++ )
{
// open socket on port 25 to mxhosts, setting
// returned file pointer to the variable 'fp'
$fp = fsockopen ( $mxhosts[$i], 25 );
// if the 'fp' was set, then goto work
if ( $fp )
{
// work variables
$s = 0;
$c = 0;
$out = "";
// set our created socket for 'fp' to
// non-blocking mode
// so our fgets() calls will return
// right away
set_socket_blocking ( $fp, false );
// as long as our 'out' variable has a
// null value ("")
// keep looping (do) until we get
// something
//
do
{
// output of the stream assigned
// to 'out' variable
$out = fgets ( $fp, 2500 );
// if we get an "220" code (service ready code (i.e greeting))
// increment our work (code (c)) variable, and null
// out our output variable for a later loop test
//
if ( ereg ( "^220", $out ) )
{
$s = 0;
$out = "";
$c++;
$return[2] = true;
$return[3] = $mxhosts[$i];
}
// elseif c is greater than 0
// and 'out' is null (""),
// we got a code back from some
// server, and we've passed
// through this loop at least
// once
else if ( ( $c > 0 ) && ( $out == "" ) )
{
$return[2] = true;
break;
}
// else increment our 's'
// counter
else
{ $s++; }
// and if 's' is 9999, break, to
// keep from looping
// infinetly
if ( $s == 9999 ) { break; }
} while ( $out == "" );
// reset our file pointer to blocking
// mode, so we wait
// for communication to finish before
// moving on...
set_socket_blocking ( $fp, true );
// talk to the MX mail server,
// validating ourself (HELO)
fputs ( $fp, "HELO $SERVER_NAME\n" );
// get the mail servers reply, assign to
// 'output' (ignored)
$output = fgets ( $fp, 2000 );
// give a bogus "MAIL FROM:" header to
// the server
fputs ( $fp, "MAIL FROM: <nobody@" . $SERVER_NAME . ">\n" );
// get output again (ignored)
$output = fgets ( $fp, 2000 );
// give RCPT TO: header for the email
// address we are testing
fputs ( $fp, "RCPT TO: <$email>\n" );
// get final output for validity testing
// (used)
$output = fgets ( $fp, 2000 );
// test the reply code from the mail
// server for the 250 (okay) code
if ( ereg ( "^250", $output ) )
{
// set our true/false(ness)
// array item for testing
$return[0] = true;
}
else
{
// otherwise, bogus address,
// fillin the 2nd array item
// with the mail servers reply
// code for user to test if they
// want
$return[0] = false;
$return[1] = $output;
}
// tell the mail server we are done
// talking to it
fputs ( $fp, "QUIT\n" );
// close the file pointer
fclose( $fp );
// if we got a good value break,
// otherwise, we'll keep
// trying MX records until we get a good
// value, or we
// exhaust our possible MX servers
if ( $return[0] == true )
{
$bSuccess = true;
break;
}
}
}
}
}
}
// return the array for the user to test against
return $return;
}
?>
]]>