EmailAddress.php

<?php
declare(strict_types=1);

namespace Acme\Domain\Type;

use function Assert\that;

class EmailAddress
{
    /** @var string */
    private $email;

    public function __construct(string $email)
    {
        that($email)->email();

        $this->email = $email;
    }

    public function get(): string
    {
        return $this->email;
    }
    
    public function __toString(): string
    {
        return $this->get();
    }
}

Assert package: https://github.com/beberlei/assert