liwo/app/Http/Controllers/NewAuthController.php

<?php

namespace App\Http\Controllers;

use Illuminate\Http\Request;

class NewAuthController extends Controller
{
    public function emailChecking()
    {
        if (1) {
            // email exists in db
        }

        if (2) {
            // email exists in cache
        }

        if (3) {
            // email exists in invite table
        }

        if (4) {
            // none of above
        }
    }
}