Ошибка при отправке письма с формы обратной связи yii2

http://s16.radikal.ru/i191/1709/91/19cbbb872dcb.png "скриншот ошибки"

Весь нужный код

ContactForm модель

<?php
/* @var $this yii\web\View */
/* @var $form yii\bootstrap\ActiveForm */
/* @var $model app\models\ContactForm */
use yii\helpers\Html;
use yii\bootstrap\ActiveForm;
use yii\captcha\Captcha;
$this->title = 'Contact';
$this->params['breadcrumbs'][] = $this->title;
?>
<div class="site-contact container">
    <h1><?= Html::encode($this->title) ?></h1>
    <?php if (Yii::$app->session->hasFlash('contactFormSubmitted')): ?>
        <div class="alert alert-success">
            Thank you for contacting us. We will respond to you as soon as possible.
        </div>
        <p>
            Note that if you turn on the Yii debugger, you should be able
            to view the mail message on the mail panel of the debugger.
            <?php if (Yii::$app->mailer->useFileTransport): ?>
                Because the application is in development mode, the email is not sent but saved as
                a file under <code><?= Yii::getAlias(Yii::$app->mailer->fileTransportPath) ?></code>.
                Please configure the <code>useFileTransport</code> property of the <code>mail</code>
                application component to be false to enable email sending.
            <?php endif; ?>
        </p>
    <?php else: ?>
        <p>
            If you have business inquiries or other questions, please fill out the following form to contact us.
            Thank you.
        </p>
        <div class="row">
            <div class="col-lg-5">
                <?php $form = ActiveForm::begin(['id' => 'contact-form']); ?>
                    <?= $form->field($model, 'name')->textInput(['autofocus' => true]) ?>
                    <?= $form->field($model, 'email') ?>
                    <?= $form->field($model, 'subject') ?>
                    <?= $form->field($model, 'body')->textarea(['rows' => 6]) ?>
                    <?= $form->field($model, 'verifyCode')->widget(Captcha::className(), [
                        'template' => '<div class="row"><div class="col-lg-3">{image}</div><div class="col-lg-6">{input}</div></div>',
                    ]) ?>
                    <div class="form-group">
                        <?= Html::submitButton('Submit', ['class' => 'btn btn-primary', 'name' => 'contact-button']) ?>
                    </div>
                <?php ActiveForm::end(); ?>
            </div>
        </div>
    <?php endif; ?>
</div>

Экшн в SiteController

public function actionContact()
    {   
        $model = new ContactForm();
        if ($model->load(Yii::$app->request->post()) && $model->contact(Yii::$app->params['emailto'])) {
            Yii::$app->session->setFlash('contactFormSubmitted');
            return $this->refresh();
        }
        return $this->render('contact', [
            'model' => $model,
        ]);
    }

contact.php Вид

<?php
/* @var $this yii\web\View */
/* @var $form yii\bootstrap\ActiveForm */
/* @var $model app\models\ContactForm */
use yii\helpers\Html;
use yii\bootstrap\ActiveForm;
use yii\captcha\Captcha;
$this->title = 'Contact';
$this->params['breadcrumbs'][] = $this->title;
?>
<div class="site-contact container">
    <h1><?= Html::encode($this->title) ?></h1>
    <?php if (Yii::$app->session->hasFlash('contactFormSubmitted')): ?>
        <div class="alert alert-success">
            Thank you for contacting us. We will respond to you as soon as possible.
        </div>
        <p>
            Note that if you turn on the Yii debugger, you should be able
            to view the mail message on the mail panel of the debugger.
            <?php if (Yii::$app->mailer->useFileTransport): ?>
                Because the application is in development mode, the email is not sent but saved as
                a file under <code><?= Yii::getAlias(Yii::$app->mailer->fileTransportPath) ?></code>.
                Please configure the <code>useFileTransport</code> property of the <code>mail</code>
                application component to be false to enable email sending.
            <?php endif; ?>
        </p>
    <?php else: ?>
        <p>
            If you have business inquiries or other questions, please fill out the following form to contact us.
            Thank you.
        </p>
        <div class="row">
            <div class="col-lg-5">
                <?php $form = ActiveForm::begin(['id' => 'contact-form']); ?>
                    <?= $form->field($model, 'name')->textInput(['autofocus' => true]) ?>
                    <?= $form->field($model, 'email') ?>
                    <?= $form->field($model, 'subject') ?>
                    <?= $form->field($model, 'body')->textarea(['rows' => 6]) ?>
                    <?= $form->field($model, 'verifyCode')->widget(Captcha::className(), [
                        'template' => '<div class="row"><div class="col-lg-3">{image}</div><div class="col-lg-6">{input}</div></div>',
                    ]) ?>
                    <div class="form-group">
                        <?= Html::submitButton('Submit', ['class' => 'btn btn-primary', 'name' => 'contact-button']) ?>
                    </div>
                <?php ActiveForm::end(); ?>
            </div>
        </div>
    <?php endif; ?>
</div>

конфиг web php

<?php
$params = require(__DIR__ . '/params.php');
$db = require(__DIR__ . '/db.php');
$config = [
    'id' => 'basic',
    'basePath' => dirname(__DIR__),
    'bootstrap' => ['log'],
    'language' => 'ru-Ru',
    'defaultRoute' => 'category/index',
    'modules' => [
        'admin'=> [
            'class' => 'app\modules\admin\Module',
            'layout' => 'admin',
            'defaultRoute' => 'order/index',
        ],
    ],
    'components' => [
        'request' => [
            // !!! insert a secret key in the following (if it is empty) - this is required by cookie validation
             'cookieValidationKey' => 'x-1-dG8bPnfzhDXyt_NmRlbeEmX6SrTG',
            'baseUrl' => '',
        ],
        'cache' => [
            'class' => 'yii\caching\FileCache',
        ],
        'user' => [
            'identityClass' => 'app\models\User',
            'enableAutoLogin' => true,
            /*'loginUrl' => 'cart/view',*/
        ],
        'errorHandler' => [
            'errorAction' => 'site/error',
        ],
        '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.mail.ru',
                'username' => 'ser588583',
                'password' => 's570224',
                'port' => '465',
                'encryption' => 'ssl',
            ],
        ],
        'log' => [
            'traceLevel' => YII_DEBUG ? 3 : 0,
            'targets' => [
                [
                    'class' => 'yii\log\FileTarget',
                    'levels' => ['error', 'warning'],
                ],
            ],
        ],
        'db' => $db,
        'urlManager' => [
            'enablePrettyUrl' => true,
            'showScriptName' => false,
            'rules' => [
            //Ссылка категорий, где category наш контроллер
            'category/<id:\d+>/page/<page:\d+>' => 'category/view',
            'category/<id:\d+>' => 'category/view',
            'product/<id:\d+>' => 'product/view',
            'search' => 'category/search',
            ],
        ],
    ],
    'controllerMap' => [
        'elfinder' => [
            'class' => 'mihaildev\elfinder\PathController',
            'access' => ['@'],
            'root' => [
                'baseUrl'=>'/web',
           /*     'basePath'=>'@webroot',*/
                'path' => 'upload/global',
                'name' => 'Global'
            ],
        ]
    ],
    'params' => $params,
];
if (!YII_ENV_TEST) {
    // configuration adjustments for 'dev' environment
    $config['bootstrap'][] = 'debug';
    $config['modules']['debug'] = [
        'class' => 'yii\debug\Module',
        'allowedIPs' => ['*'],
    ];
    $config['bootstrap'][] = 'gii';
    $config['modules']['gii'] = [
        'class' => 'yii\gii\Module',
        'allowedIPs' => ['*'],
    ];
}   

return $config;