Email validation using Regular Expression

Following code shows how to validate email in php.

<?php // chek email validation
if (!preg_match('/^[^0-9][a-zA-Z0-9_]+([.][a-zA-Z0-9_]+)*[@][a-zA-Z0-9_]+([.][a-zA-Z0-9_]+)*[.][a-zA-Z]{2,4}$/',$_POST['email']))
{
echo "invalid Email Address";
}
?>