1、commom下main-local.php配置：

'mailer' => [
            'class' => 'yii\swiftmailer\Mailer',
            'viewPath' => '@common/mail',
            // 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.qq.com',
                'username'=>'邮箱',
                'password'=>'smtp密码非邮箱密码',
                'port'=>'465',
                'encryption'=>'ssl',
            ],
        ],

2、commom下params.php的管理员邮箱需要和上面的邮箱账号一致：

return [
    'adminEmail' => '邮箱',
    'supportEmail' => '',
    'user.passwordResetTokenExpire' => 3600,
];

3、配置好后，邮件发送基本上可以用，后面就是根据自己的喜好修改邮件的模板。