Why did mail stop working on the server?

Question

linux

On the server mail always went normally and now goes on other projects. But it stopped there (at what it works locally, oddly enough, through xampp).
Here is the code:

private function sendEmailRecovery($email, $recoveryCode){

        Yii::$app->mailer->compose('recovery/pass.php', [
            'recoveryCode' => $recoveryCode,
            'urlRec' => Url::to(['hash/getter'], true),
        ])
            ->setFrom(Yii::$app->params['mainEmailSender'])
            ->setTo($email)
            ->setSubject('восстановление пароля')
            ->send();
    }

I can't even figure out where to look...

Answer 1

For starters - in the mail logs