How to correctly fix phpMailer max execution time error?

Question

I'm using phpMailer for sending emails from localhost, but I have had to do a quick fix to its main class to get it working.

When I just downloaded phpmailer and used it, i got a max execution time error in my script:

Fatal error: Maximum execution time of 30 seconds exceeded in /home/lol/desktop/web/mailtest/class.phpmailer.php on line 737

So, i went to line 737 in class.phpmailer.php and found a function to validate address:

public static function ValidateAddress($address) {
if ((defined('PCRE_VERSION')) && (version_compare(PCRE_VERSION, '8.0') >= 0)) {
  return preg_match('/^(?!(?>(?1)"?(?>\\\[ -~]|[^"])"?(?1)){255,})(?!(?>(?1)"?(?>\\\[ -~]|[^"])"?(?1)){65,}@)((?>(?>(?>((?>(?>(?>\x0D\x0A)?[     ])+|(?>[    ]*\x0D\x0A)?[   ]+)?)(\((?>(?2)(?>[\x01-\x08\x0B\x0C\x0E-\'*-\[\]-\x7F]|\\\[\x00-\x7F]|(?3)))*(?2)\)))+(?2))|(?2))?)([!#-\'*+\/-9=?^-~-]+|"(?>(?2)(?>[\x01-\x08\x0B\x0C\x0E-!#-\[\]-\x7F]|\\\[\x00-\x7F]))*(?2)")(?>(?1)\.(?1)(?4))*(?1)@(?!(?1)[a-z0-9-]{64,})(?1)(?>([a-z0-9](?>[a-z0-9-]*[a-z0-9])?)(?>(?1)\.(?!(?1)[a-z0-9-]{64,})(?1)(?5)){0,126}|\[(?:(?>IPv6:(?>([a-f0-9]{1,4})(?>:(?6)){7}|(?!(?:.*[a-f0-9][:\]]){7,})((?6)(?>:(?6)){0,5})?::(?7)?))|(?>(?>IPv6:(?>(?6)(?>:(?6)){5}:|(?!(?:.*[a-f0-9]:){5,})(?8)?::(?>((?6)(?>:(?6)){0,3}):)?))?(25[0-5]|2[0-4][0-9]|1[0-9]{2}|[1-9]?[0-9])(?>\.(?9)){3}))\])(?1)$/isD', $address);
} elseif (function_exists('filter_var')) { //Introduced in PHP 5.2
    if(filter_var($address, FILTER_VALIDATE_EMAIL) === FALSE) {
      return false;
    } else {
      return true;
    }
} else {
    return preg_match('/^(?:[\w\!\#\$\%\&\'\*\+\-\/\=\?\^\`\{\|\}\~]+\.)*[\w\!\#\$\%\&\'\*\+\-\/\=\?\^\`\{\|\}\~]+@(?:(?:(?:[a-zA-Z0-9_](?:[a-zA-Z0-9_\-](?!\.)){0,61}[a-zA-Z0-9_-]?\.)+[a-zA-Z0-9_](?:[a-zA-Z0-9_\-](?!$)){0,61}[a-zA-Z0-9_]?)|(?:\[(?:(?:[01]?\d{1,2}|2[0-4]\d|25[0-5])\.){3}(?:[01]?\d{1,2}|2[0-4]\d|25[0-5])\]))$/', $address);
}
}

This is the famous line 737:

return preg_match('/^(?!(?>(?1)"?(?>\\\[ -~]|[^"])"?(?1)){255,})(?!(?>(?1)"?(?>\\\[ -~]|[^"])"?(?1)){65,}@)((?>(?>(?>((?>(?>(?>\x0D\x0A)?[   ])+|(?>[    ]*\x0D\x0A)?[   ]+)?)(\((?>(?2)(?>[\x01-\x08\x0B\x0C\x0E-\'*-\[\]-\x7F]|\\\[\x00-\x7F]|(?3)))*(?2)\)))+(?2))|(?2))?)([!#-\'*+\/-9=?^-~-]+|"(?>(?2)(?>[\x01-\x08\x0B\x0C\x0E-!#-\[\]-\x7F]|\\\[\x00-\x7F]))*(?2)")(?>(?1)\.(?1)(?4))*(?1)@(?!(?1)[a-z0-9-]{64,})(?1)(?>([a-z0-9](?>[a-z0-9-]*[a-z0-9])?)(?>(?1)\.(?!(?1)[a-z0-9-]{64,})(?1)(?5)){0,126}|\[(?:(?>IPv6:(?>([a-f0-9]{1,4})(?>:(?6)){7}|(?!(?:.*[a-f0-9][:\]]){7,})((?6)(?>:(?6)){0,5})?::(?7)?))|(?>(?>IPv6:(?>(?6)(?>:(?6)){5}:|(?!(?:.*[a-f0-9]:){5,})(?8)?::(?>((?6)(?>:(?6)){0,3}):)?))?(25[0-5]|2[0-4][0-9]|1[0-9]{2}|[1-9]?[0-9])(?>\.(?9)){3}))\])(?1)$/isD', $address);

It has a regular expression long as hell which I think caused my script to time out, so i deleted the if condition, and left new PHP filter_var function to verify email, like that:

public static function ValidateAddress($address) {
if (function_exists('filter_var')) { //Introduced in PHP 5.2
    if(filter_var($address, FILTER_VALIDATE_EMAIL) === FALSE) {
      return false;
    } else {
      return true;
    }
} else {
    return preg_match('/^(?:[\w\!\#\$\%\&\'\*\+\-\/\=\?\^\`\{\|\}\~]+\.)*[\w\!\#\$\%\&\'\*\+\-\/\=\?\^\`\{\|\}\~]+@(?:(?:(?:[a-zA-Z0-9_](?:[a-zA-Z0-9_\-](?!\.)){0,61}[a-zA-Z0-9_-]?\.)+[a-zA-Z0-9_](?:[a-zA-Z0-9_\-](?!$)){0,61}[a-zA-Z0-9_]?)|(?:\[(?:(?:[01]?\d{1,2}|2[0-4]\d|25[0-5])\.){3}(?:[01]?\d{1,2}|2[0-4]\d|25[0-5])\]))$/', $address);
}
}

Now my code send the email correctly using GMAIL smtp server from localhost. But: Will this modification suppose a security risk for my application?, is there any other way to fix it?

Thanks in advance guys, sorry for that large piece of copied code.