3dealer/app/Mail/EmailChangedNoticeMail.php

<?php

namespace App\Mail;

use Illuminate\Mail\Mailable;
use Illuminate\Mail\Mailables\Content;
use Illuminate\Mail\Mailables\Envelope;

/**
 * Sent to the OLD address once the login email has changed (see
 * Account\EmailController), so the owner notices a takeover. The new address
 * is shown masked, e.g. "n•••@example.com".
 */
class EmailChangedNoticeMail extends Mailable
{
    public readonly string $maskedEmail;

    public function __construct(string $newEmail)
    {
        [$local, $domain] = explode('@', $newEmail, 2);

        $this->maskedEmail = mb_substr($local, 0, 1).'•••@'.$domain;
    }

    public function envelope(): Envelope
    {
        return new Envelope(subject: 'Το email του λογαριασμού σου άλλαξε');
    }

    public function content(): Content
    {
        return new Content(view: 'emails.email-changed-notice');
    }
}