Laravel App\Mail - Invalid argument supplied for foreach() - Mail

I'm facing a problem with App\Mail::.

Mail::to(['...@gmail.com'])->send(new NewOrdersRegistered('', ''));

How the hell this gives an Error Exception > Invalid argument supplied for foreach()?

I also tried:

Mail::to('...@gmail.com')->send(new NewOrdersRegistered('', ''));

The Laravel code that gives exception is:

protected function buildRecipients($message){
    foreach (['to', 'cc', 'bcc', 'replyTo'] as $type) {
        foreach ($this->{$type} as $recipient) {
            $message->{$type}($recipient['address'], $recipient['name']);
        }
    }
    return $this;
}

But got the same error! I have the same code in another project that runs like a charm.

Thanks for any help given.

Controller:

<?php

namespace App\Http\Controllers;

use App\Lamimail;
use App\LamimailOrders;
use App\LamimailLines;
use Illuminate\Http\Request;
use Illuminate\Support\Facades\Validator;
use Illuminate\Support\Facades\Mail;
use App\Mail\NewOrdersRegistered;
use PDO;
use DB;
use Auth;


class LamimailController extends Controller
{
    /**
     * Instantiate a new controller instance.
     *
     * @return void
     */
    public function __construct()
    {
        // calls the middleware: SetDatabaseConnection
        $this->middleware('SetDatabaseConnection:lamimail');
    }

    /**
     * Obtem todas as encomendas (+linhas) em aberto no AS400 e insere na db caso não existam
     */
    public function cronjob1_execute ()
    {
        // Obtem os Utilizadores do Grupo Expedição
        $utilizadores_expedic = DB::connection('lamiapps')->table('tbl_users')->select('email')->where('group_id', '=', 3)->get();

        //dd($utilizadores_expedic);

        //dd($utilizadores_expedic[0]->name);
        Mail::to($utilizadores_expedic->email)->send(new NewOrdersRegistered('', ''));

        dd('end');

    }

    /**
     * Display a listing of the resource.
     *
     * @return \Illuminate\Http\Response
     */
    public function index()
    {
        return view('lamimail.index');
    }
}