src/OwpUsers.inc.php
public function userExistsViaEmail($email)
    {
        $query_sql = "
            SELECT COUNT(*)
            FROM tbl_users
            WHERE LCASE(tbl_users.email) = LCASE('" . filter_var($email, FILTER_SANITIZE_EMAIL) . "')
            LIMIT 1";

        return (boolean)((int)$this->OwpDBMySQLi->get_var($query_sql) ? true : false);

    }
public function userExistsViaEmail($email)
    {
        $query_sql = "
            SELECT COUNT(*)
            FROM tbl_users
            WHERE LCASE(tbl_users.email) = LCASE('" . filter_var($email, FILTER_SANITIZE_EMAIL) . "')
            LIMIT 1";

        return (boolean)((int)$this->OwpDBMySQLi->get_var($query_sql) ? true : false);

    }
userExistsViaEmail

@method userExistsViaEmail($email) Check if user exists via email
@access public
@param  string $email Valid user email address
@return boolean

@author  Brian Tafoya <btafoya@briantafoya.com>
@version 1.0