codejobs - Validate an email - PHP

email.php

<?php
function isEmail($email) {
	if((strlen($email) >= 6) and (substr_count($email, "@") === 1) and (substr($email, 0, 1) !== "@") and (substr($email, strlen($email) - 1, 1) !== "@")) { 
		if((!strstr($email, "'")) and (!strstr($email, "\"")) and (!strstr($email, "\\")) and (!strstr($email, "\$")) and (!strstr($email, " "))) {
			if(substr_count($email, ".") >= 1) {
				$domain = substr(strrchr($email, "."), 1);
				
				if(strlen($domain) > 1 and strlen($domain) < 5 and (!strstr($domain, "@"))) {
					$prev = substr($email, 0, strlen($email) - strlen($domain) - 1);
					$last = substr($prev, strlen($prev) - 1, 1);
					
					if($last !== "@" and $last !== ".") {
						return TRUE;					
					}
				}
			}
		}
	}
	
	return FALSE;	
}
?>