Message::scoreShortHead

protected function scoreShortHead(&$head)
{
	$score = 0;

	$regex = '/(?:^|n)
		(?.{5,50}d),?x20
		[^dn]{0,20}(?d{1,2}:d{2}(?::d{2})?x20?(?:am|pm)?),?x20
		(?.+):s*$
	/ix'.BX_UTF_PCRE_MODIFIER;
	if (preg_match($regex, $head, $matches))
	{
		$matches['date'] = trim($matches['date']);
		if (strtotime($matches['date']) !== false)
		{
			$score++;
		}
		else if (preg_match('/^[^x20]+x20+((?:[^x20]+x20+)?(.+))$/', $matches['date'], $date))
		{
			if (strtotime($date[1]) !== false || strtotime($date[2]) !== false)
				$score++;
		}

		if (preg_match('/([a-zd_](.?[a-zd_-]+)*)?[a-zd_]@(([a-zd][a-zd-]*)?[a-zd].?)+/i', $matches['from']))
			$score++;
	}

	return $score;
}