Express使用Nodemailer发送邮件出现重复空白邮件如何解决

• 代码中连续调用了两次transporter.sendMail方法，因此会发出两封邮件
• 第一次调用await transporter.sendMail({ 完整配置 })时，已经成功发出了第一封内容、收件人正常的邮件，该方法返回的是邮件发送成功的响应结果，并非发信配置对象
• 第二次调用transporter.sendMail(mail)时，传入的mail是上一步的响应结果，不属于合法发信配置，因此会发出收件人、内容异常的空白邮件

删除多余的第二次transporter.sendMail调用即可，如果需要捕获发送结果、打印日志，直接在第一次调用位置处理，两种写法可选：

1. 保留await写法，直接打印返回结果：

console.log('called')
let transporter = nodemailer.createTransport({
  host: 'smtp.gmail.com',
  port: 465,
  secure: true, // true for 465, false for other ports
  auth: {
    user: process.env.MAIL,
    pass: process.env.MAIL_PASSWORD,
  },
})

let message = ''
switch (format) {
  case 'resetPassword':
    message = `There was recently a request to change the password for your account. If you requested this password change, click the link below to reset your password:
<br><br><a href="${passwordKey}">${passwordKey}</a><br><br>

If you did not make this request, you can ignore this message and your password will remain the same.`
    break

  default:
    break
}
// 仅保留一次sendMail调用，直接打印返回的发送结果
let mailSendResult = await transporter.sendMail({
  from: `<${process.env.MAIL}>`,
  to: email,
  bcc: process.env.MAIL,
  subject: subject,
  html: message,
})
console.log(mailSendResult)

2. 用then链式调用，无需await接收：

// 省略前面transporter创建、message生成的相同代码
transporter.sendMail({
  from: `<${process.env.MAIL}>`,
  to: email,
  bcc: process.env.MAIL,
  subject: subject,
  html: message,
}).then((mailSendResult) => {
  console.log(mailSendResult)
})

内容的提问来源于stack exchange，提问作者GlassesUSA