Too many IFs?

Can someone tell me if this is excessive use of IF statement?

Thanks.

if ($role == 'admin') {

    // Check if the user exist
    if (isset($_POST['user_email']) && !empty($_POST['user_email'])) {

        // Sanitize the data
        $user_email_data = trim(strip_tags(stripslashes($_POST['user_email'])));

        // Now use PHP to check for validation
        if (filter_var($user_email_data, FILTER_VALIDATE_EMAIL)) {
            if (false == get_user_by('email', $user_email_data)) {
                // the user doesn't exist
            } else {
                // the user exists
                update_user_meta($userID, 'wp_user_roles', '10');
                // check wp if the new value has been stored
                if (get_user_meta($userID, 'wp_user_roles', true) != '10') {
                    wp_die('An error occured!');
                }
            }
        }
    }
} else {
    // Do nothing, exit
    exit ;
}