//WRONG
$customer_array = Array(
   '1' => 'dbcrizzer@gmail.com', 'joe@ceceliasristorante.com',
);
//RIGHT
$customer_array = Array(
   '1' => 'dbcrizzer@gmail.com',
   '2' => 'joe@ceceliasristorante.com'
);

//REAL RIGHT IN YOUR CASE
$customer_array = Array(
   '1' => 'dbcrizzer@gmail.com, joe@ceceliasristorante.com'
);