Node.js nodemailer

我将node.js与nodemailer一起使用，并且我得到的是这样：

let mail = await new Promise((resolve,reject)=>{
  transporter.sendMail(mailOptions, (error, info) => {
    if (error) {
        console.log(error);
        reject(error);
    } else {
        res.status(200).json({ "success": true, "message": 'Thank you for your registration! We\'ve sent you an email to confirm!' });
        resolve(mail);
    }
  });
});

它正在发送邮件，但出现此错误：

/home/project/controllers/signup.js:139
                        resolve(mail);
                                ^
ReferenceError: mail is not defined
    at transporter.sendMail (/home/project/controllers/signup.js:139:15)
    at transporter.send.args (/home/project/node_modules/nodemailer/lib/mailer/index.js:226:21)
    at callback (/home/project/node_modules/nodemailer/lib/sendmail-transport/index.js:90:28)
    at ChildProcess.sendmail.once.code (/home/project/node_modules/nodemailer/lib/sendmail-transport/index.js:131:28)
    at Object.onceWrapper (events.js:286:20)
    at ChildProcess.emit (events.js:198:13)
    at Process.ChildProcess._handle.onexit (internal/child_process.js:248:12)
[nodemon] app crashed - waiting for file changes before starting...

此解析（邮件）是否不合法？

let mail = await new Promise((resolve,reject)=>{
  transporter.sendMail(mailOptions, (error, info) => {
    if (error) {
        console.log(error);
        reject(error);
    } else {
        res.status(200).json({ "success": true, "message": 'Thank you for your registration! We\'ve sent you an email to confirm!' });
        // change below
        resolve(info);
    }
  });
});

上面的内容应该适合您使用传递给info方法的sendMail进行解析。