Why does encoding fail?

Question

Yii

The Yii2 project is configured to send error messages to email. But instead of Russian letters, hieroglyphs are obtained (

The encoding is standard, utf-8
Config with sending settings:

'mailer' => [
            'class' => 'yii\swiftmailer\Mailer',
            // send all mails to a file by default. You have to set
            // 'useFileTransport' to false and configure a transport
            // for the mailer to send real emails.
            'useFileTransport' => false,
            'transport' => [
                'class' => 'Swift_SmtpTransport',
                'host' => 'smtp.***.ru',
                'port' => '25',
                'encryption' => 'tls',
            ],
        ],

What can be wrong?

Answer 1

Project from github from our smaller squint brothers