没有明显原因，MailGun参数无效

Question

I have a very simple code that uses MailGun in my Symfony2 application:

public function sendNewEmail()
{
    $message = \Swift_Message::newInstance()
                    ->setSubject('Any random subject')
                    ->setFrom('[e-mail]')
                    ->setTo('[e-mail]')
                    ->setBody('Mybody');
    $this->mailer->send($message);

    return null;
}

This code use to work very fine, but after some days ago it simply doesn't work anymore. It returns the error in the end.

I have no idea of what this problem can be once I haven't changed almost anything in code.

How could I discover what is?

request.CRITICAL: Uncaught PHP Exception Mailgun\Connection\Exceptions\MissingRequiredParameters: "The parameters passed to the API were invalid. Check your inputs! Sandbox subdomains are for test purposes only. Please add your own domain or add the address to authorized recipients in domain settings." at /srv/www/MyCodeSource/vendor/mailgun/mailgun-php/src/Mailgun/Connection/RestClient.php line 169 {"exception":"[object] (Mailgun\Connection\Exceptions\MissingRequiredParameters(code: 0): The parameters passed to the API were invalid. Check your inputs! Sandbox subdomains are for test purposes only. Please add your own domain or add the address to authorized recipients in domain settings. at /srv/www/MyCodeSource/vendor/mailgun/mailgun-php/src/Mailgun/Connection/RestClient.php:169)"} []

Answer 1

Yeah, it looks like it was the sandbox domain that I was using that was causing the problem.

I added a custom domain and added the entries in my DNS, etc... and now it's working

But the weirdest is that I was using it for months and I've never had this problem. When, maybe it was an exception that was eventually fixed by MailGun.

---

Update Just to confirm what I said above: I received an email of MailGun

We've implemented changes that were announced and several notifications were sent out informing customers starting from November 1st. On December 1st, 2016...All domains, regardless of the creation date, will be required to verify the domain to continue sending and receiving messages.

That is why my email stopped suddenly. And after they explained that I should change the domain, set the DNS configuration, etc...

And well, they sent the instructions after I've done them, but they had a nice, fast and clear support. Just giving the credit...