Expected response code 250 but got code "554", with message "554 Sandbox subdomains are for test purposes only."?

Question

API

Set up email sending, Laravel 5.4, Homestead.

Mail::to('[email protected]')->send(new Registered(Auth::user()));

ERROR

Expected response code 250 but got code "554", with message "554 Sandbox subdomains are for test purposes only. Please add your own domain or add the address to authorized recipients in Account Settings. "

In docks it is written that should work even locally.

Mail & Local Development
When developing an application that sends email, you probably don't want to actually send emails to live email addresses. Laravel provides several ways to "disable" the actual sending of emails during local development.

And it does not even send so there is nothing to turn off.
If hosted on a live site with a real domain name, the live site will throw the same error.

Answer 1

This message is from mailgun, by default it is registered in /config/mail.php and in .env what settings you use.
If you want to send mail using the php function (or rather, the SwiftMail wrapper is still used), then in the config or in .env put the mail driver in mail .