'mailer' => [
           'class' => 'yiiswiftmailerMailer',
            'viewPath' => '@common/mail',
            'useFileTransport' => false,
            'transport' => [
                'class' => 'Swift_SmtpTransport',
                'host' => 'smtp.yandex.ru',
                'username' => 'test@prioriticlub.ru',
                'password' => 'password',
                'port' => '587',
                'encryption' => 'TLS',
            ],
        ],

Expected response code 250 but got code "553", with message "553 5.7.1 Sender address rejected: not owned by auth user."

'mailer' => [
        'class' => 'yiiswiftmailerMailer',
          'viewPath' => '@app/mail',
          'transport' => [
              'class' => 'Swift_SmtpTransport',
              'host' => 'smtp.yandex.ru',
              'username' => 'test@yandex.ru',
              'password' => '**********',
              'port' => 465,
              'encryption' => 'ssl',
          ],
          'useFileTransport' => false,
    ],

public function contact($email)
{
    $content = "<p>Email: " . $this->email . "</p>";
    $content .= "<p>Name: " . $this->name . "</p>";
    $content .= "<p>Subject: " . $this->subject . "</p>";
    $content .= "<p>Body: " . $this->body . "</p>";
    if ($this->validate()) {
        Yii::$app->mailer->compose("@app/mail/layouts/html", ["content" => $content])
            ->setTo('test@yandex.ru')
            ->setFrom([Yii::$app->params['supportEmail'] => $this->name])
            ->setSubject($this->subject)
             ->setTextBody($this->body)
             ->send();

        return true;
    }
    return false;
}

return [
    'adminEmail' => 'test@yandex.ru',
    'supportEmail' => 'test@yandex.ru',
];

public function actionContact()
{
    /* Создаем экземпляр класса */
    $model = new ContactForm();
    /* получаем данные из формы и запускаем функцию отправки contact, если все хорошо, выводим сообщение об удачной отправке сообщения на почту */
    if ($model->load(Yii::$app->request->post()) && $model->contact(Yii::$app->params['adminEmail'])) {
        Yii::$app->session->setFlash('contactFormSubmitted');
        return $this->refresh();
    /* иначе выводим форму обратной связи */
    } else {
        return $this->render('contact', [
            'model' => $model,
        ]);
    }
}