Why is Yii2 sending emails via mail() and not via smtp even though smtp is configured?

Question

Yii

'mailer' => [
            'class' => 'yii\swiftmailer\Mailer',
         'transport' => [
                'class' => 'Swift_SmtpTransport',
                'host' => '**',
                'username' => '**',
                'password' => '**',
                'port' => '25',
            ],
            'useFileTransport' => false,
        ],

Here is the code from the config. There is no encryption on smtp. When I send a letter, it does not send via smtp, but simply as if via mail. I see it in the header of the email. What are the options. And what should be checked?

Answer 1

Doesn't send yii anything via mail. Give the code of the place where the sending goes, I'm ready to argue that it is there that the sending via mail goes bypassing the mailer