'components' => [
        'mailer' => [
            'class' => 'yii\swiftmailer\Mailer',
            'viewPath' => '@common/mail',
            'useFileTransport' => false,
            'transport' => [
                'class' => 'Swift_SmtpTransport',
                'host' => 'smtp.163.com',
                'username' => '
 
[email protected]',
                'password' => '00000000',
                'port' => '25',
                'encryption' => 'tls',
            ],
        ],

在 config中新增 上述配置

    public function actionSendMail()
    {
        $content = "<div><p>XXXXXXXXX</p><p>XXXXXXXXX</p><p>XXXXXXXXX</p><p>XXXXXXXXX</p><p>XXXXXXXXX</p><p>XXXXXXXXX</p><p>XXXXXXXXX</p><p>XXXXXXXXX</p><p>XXXXXXXXX</p><p>XXXXXXXXX</p><p>XXXXXXXXX</p><p>XXXXXXXXX</p><p>XXXXXXXXX</p><p>XXXXXXXXX</p><p>XXXXXXXXX</p><p>XXXXXXXXX</p><p>XXXXXXXXX</p><p>XXXXXXXXX</p><p>XXXXXXXXX</p><p>XXXXXXXXX</p><p>XXXXXXXXX</p><p>XXXXXXXXX</p><p>XXXXXXXXX</p><p>XXXXXXXXX</p><p>XXXXXXXXX</p><p>XXXXXXXXX</p><p>XXXXXXXXX</p><p>XXXXXXXXX</p><p>XXXXXXXXX</p><p>XXXXXXXXX</p><p>XXXXXXXXX</p><p>XXXXXXXXX</p><p>XXXXXXXXX</p><p>XXXXXXXXX</p><p>XXXXXXXXX</p><p>XXXXXXXXX</p><p>XXXXXXXXX</p><p>XXXXXXXXX</p><p>XXXXXXXXX</p><p>XXXXXXXXX</p><p>XXXXXXXXX</p><p>XXXXXXXXX</p><p>XXXXXXXXX</p></div>";
        \Yii
 
::$app->mailer->compose()
            ->setFrom('[email protected]')
            ->setTo('[email protected]')
            ->setSubject('TEST')
            ->setTextBody('測試')
            ->setHtmlBody($content)
            ->send();
    }