Sending emails from cloud functions for Firebase in angular 2 app

Question

I am trying to send emails using the Mailgun api from the firebase cloud function. I tried to implement the nodejs tutorial for the same in Cloud Function, but I always get the message "Error: Failed to process the request." Please, what am I doing wrong.

Cloud function code below:

 <pre>
  <code>
 var functions = require('firebase-functions');

 var nodemailer = require('nodemailer');

  var auth = {
  auth: {
      api_key: '###################',
       domain: 's###############g'
   }
 }
 exports.helloWorld = functions.https.onRequest((request, response) => {
  response.send("Hello from Firebase!");
  });

   var nodemailerMailgun = nodemailer.createTransport(auth);

 exports.sendEmail = functions.https.onRequest((request, response) =>{
  //app.get('/', function(req, res) {
   test();
 });

  function test(){
     const mailOptions = {
        //Specify email data
            from: "[e-mail]",
            //The email to contact
        to: "[e-mail]",
        //Subject and text data  
        subject: 'Hello from Mailgun',
        text: 'Hello, This is not a plain-text email, I wanted to test        some spicy Mailgun sauce in NodeJS! <a href="http://0.0.0.0:3030/validate?' +     req.params.mail + '">Click here to add your email address to a mailing     list</a>'
   };
    return smtpTransport.sendMail(mailOptions).then(() => {
    console.log("It works");
  });
}
</pre>

  Thank you for your help.

Answer 1

@GokulKathirvel, . . :

. . ,

node mailgun-js.

var functions = require('firebase-functions')
var mailgun = require('mailgun-js')({apiKey, domain})

exports.sendWelcomeEmail = functions.database.ref('users/{uid}').onWrite(event => {

  // only trigger for new users [event.data.previous.exists()]
  // do not trigger on delete [!event.data.exists()]
  if (!event.data.exists() || event.data.previous.exists()) {
    return
  }

  var user = event.data.val()
  var {email} = user

  var data = {
    from: '[e-mail]',
    subject: 'Welcome!',
    html: `<p>Welcome! ${user.name}</p>`,
    'h:Reply-To': '[e-mail]',
    to: email
  }

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

https://www.automationfuel.com/firebase-functions-sending-emails/