Node.js mailgun不发送返回未定义数据的电子邮件

我正在尝试使用Angular 4、nodejs、mailgun js和mailgun在注册流上实现一个简单的电子邮件确认。问题在于邮枪发送：

mailgun.messages().send(data, function(error, body) {
        console.log(body);
    });

正在超时，前端出现以下错误：

POST http://localhost:3000/users/sendMail net::ERR_EMPTY_RESPONSE
core.js:1448 ERROR 
HttpErrorResponse {headers: HttpHeaders, status: 0, statusText: "Unknown Error", url: null, ok: false, …}
error
:
ProgressEvent {isTrusted: true, lengthComputable: false, loaded: 0, total: 0, type: "error", …}
headers
:
HttpHeaders {normalizedNames: Map(0), lazyUpdate: null, headers: Map(0)}
message
:
"Http failure response for (unknown url): 0 Unknown Error"
name
:
"HttpErrorResponse"
ok
:
false
status
:
0
statusText
:
"Unknown Error"
url
:
null
__proto__
:
HttpResponseBase

后端show now出现错误，但返回值（正文）未定义，电子邮件未发送。这是我完整的后端sendMail模块：

const api_key = '<key-f40360259dea7c667ca06d4aee956421>';
const DOMAIN = '<sandbox836cdf3cfe9c467b916fe5bb0d73e7e7.mailgun.org>';
const mailgun = require('mailgun-js')({ apiKey: api_key, domain: DOMAIN });
// ---------------- sendMail variables -----

router.post('/sendMail', (req, res, next) => {

    console.log("Email message data: " + JSON.stringify(req.body));

    const data = {
        from: 'xxxxdev@gmail.com',
        to: [req.body.email, 'xxxxxxx@gmail.com'],
        name: req.body.firstName,
        code: req.body.workshopCode,
        subject: req.body.workshopTitle,
        text: req.body.messageBody
    };

    mailgun.messages().send(data, function(error, body) {
        console.log(body);
    });
});

 sendEmailConfirmation(message) {
     const headers = new HttpHeaders();
     headers.append('Content-Type', 'application/x-www-form-urlencoded');

     this.http.post('http://localhost:3000/users/sendMail', message).subscribe((data) => {
          console.log('Mail return data: ' + data);   >>>THIS LINE IS NEVER EXECUTED<<<<<<
              },
        );
  }

现在我在后端发现了一个禁止的错误：

(node:10780) UnhandledPromiseRejectionWarning: Error: Forbidden
    at IncomingMessage.res.on (C:\connect2Server\node_modules\mailgun-js\lib\request.js:301:17)
    at IncomingMessage.emit (events.js:165:20)
    at endReadableNT (_stream_readable.js:1101:12)
    at process._tickCallback (internal/process/next_tick.js:152:19)
(node:10780) UnhandledPromiseRejectionWarning: Unhandled promise rejection. This error originated either by throwing inside of an async function without a ca
tch block, or by rejecting a promise which was not handled with .catch(). (rejection id: 2)

---

问题已解决…由mailgun凭据中的键入错误引起。复制到的“”括号…提示是禁止的错误。

您是否尝试将错误记录到mailgun API调用的回调中？您得到

ERR\u EMPTY\u响应的原因是，在发送邮件后，您从未使用类似于
res.sendStatus（200）
的命令结束请求，如果成功，或者使用
res.sendStatus（500）
的命令结束请求。@Svenskunganka我注意到了这一点，并使用（请参见编辑）res.send（“…”）。我得到以下信息：…（节点：10780）未处理PromisejectionWarning:错误：禁止
(node:10780) UnhandledPromiseRejectionWarning: Error: Forbidden
    at IncomingMessage.res.on (C:\connect2Server\node_modules\mailgun-js\lib\request.js:301:17)
    at IncomingMessage.emit (events.js:165:20)
    at endReadableNT (_stream_readable.js:1101:12)
    at process._tickCallback (internal/process/next_tick.js:152:19)
(node:10780) UnhandledPromiseRejectionWarning: Unhandled promise rejection. This error originated either by throwing inside of an async function without a ca
tch block, or by rejecting a promise which was not handled with .catch(). (rejection id: 2)