Laravel email validation rule – must have organization domain

<?php

namespace App\Rules;

use Illuminate\Contracts\Validation\Rule;

class ArtCenterEmail implements Rule
{
    /**
     * Create a new rule instance.
     *
     * @return void
     */
    public function __construct()
    {
        //
    }

    /**
     * Determine if the validation rule passes.
     *
     * @param  string  $attribute
     * @param  mixed  $value
     * @return bool
     */
    public function passes($attribute, $value)
    {
        $email_domain = preg_replace('/.+@/', '', $value);
        return $email_domain == 'artcenter.edu' || $email_domain == 'inside.artcenter.edu';
    }

    /**
     * Get the validation error message.
     *
     * @return string
     */
    public function message()
    {
        return 'You must use your ArtCenter email.';
    }
}