Send XMPP Messages using PHP

xmpp.php

<?php

error_reporting( E_ALL & ~E_STRICT );
ini_set( 'display_errors', true );

$path = dirname( __FILE__ ).'/library';
set_include_path( 
    get_include_path() . PATH_SEPARATOR . $path 
);

require_once('Zend/Loader/Autoloader.php');
$autoloader = Zend_Loader_Autoloader::getInstance();
$autoloader->setFallbackAutoloader(true);

// constants
define('XMPP_PRESENCE', false);
define('XMPP_HOST', 'example.com');
define('XMPP_PORT', 5222);
define('XMPP_USERNAME', 'username');
define('XMPP_PASSWORD', 'password');
define('XMPP_RESOURCE', 'xmpphp');
define('XMPP_SERVER', null);
define('XMPP_PRINT_LOG', true);
define('XMPP_ERROR_LEVEL', XMPPHP_Log::LEVEL_VERBOSE);

// users
$users = array(
    'employee@example.com',
    'ceo@example.com',    
);

// message
$message = 'This is a test message...'. PHP_EOL . 'File:  '.__FILE__ . PHP_EOL . 'Line:  '.__LINE__; 

echo '<pre>';
$conn = new XMPPHP_XMPP(
    XMPP_HOST, 
    XMPP_PORT, 
    XMPP_USERNAME, 
    XMPP_PASSWORD, 
    XMPP_RESOURCE, 
    XMPP_SERVER, 
    XMPP_PRINT_LOG, 
    XMPP_ERROR_LEVEL
);

try {
    $conn->connect();
    $conn->processUntil('session_start');
    
    if( XMPP_PRESENCE ) {
        $conn->presence();        
    }

    if( !empty( $users ) ) {
        foreach( $users AS $key => $value ) {
            $conn->message( $value, $message );          
        }
    }

    $conn->disconnect();
} catch(XMPPHP_Exception $e) {
    die($e->getMessage());
}