Sending mail from Firebase webapp - email

Question

var express = require('express');
var app = express();
var nodemailer=require('nodemailer');
var transporter = nodemailer.createTransport('smtps://username#gmail.com:password#smtp.gmail.com');
app.get('/sendMail', function(req,res){
var mailOptions={
to: 'receiver#gmail.com',
subject: 'Test Mail',
html: 'Testing the Mail'
}
transporter.sendMail(mailOptions,function(err,response){
if(err){
res.end('Mail not sent');
}
else{
res.end('Mail sent');
}
});
}).listen(9091);
console.log('This is running');
I am developing a firebase web app. I need to send an email via my web app. I saw some tutorials and found some code. Using the above code I am able to send emails. It runs in the port 9091. The message will be sent when the address bar has www.mywebsite.com/sendMail. But when I host this page to Firebase what changes to be done in this code, whether there must be a change in the port number?. Please help to implement this code in my web app.

Answer 1

Update 2019: Alternatively, you can use the new Trigger Email Firebase Extension (currently in beta).
As I mentioned on my comment, the problem is: your web app was built with NodeJS and you're trying to host it on a static host environment (Firebase Hosting). But Firebase also has Cloud Functions - a service that let's you run functions on a NodeJS environment. So you should deploy your app to that service instead.
It's really easy to Get Started with Cloud Functions. And since you have already set up Firebase hosting, you can simply go to that directory and set up Cloud Functions by using this command:
firebase init functions
A new folder named "functions" will be created and an index.js file will be automatically added to that folder. Now that's the file where you're going to write your functions (we're actually just gonna need 1 function triggered by HTTP to send the email).
So in order to create this function, you would no longer need Express. you can remove that and then change a bit your index.js file to add firebase-functions, so it would become:
//var express = require('express'); No longer needed
//var app = express(); No longer needed
var nodemailer=require('nodemailer');
const functions = require('firebase-functions');
var transporter = nodemailer.createTransport('smtps://username#gmail.com:password#smtp.gmail.com');
exports.sendMail = functions.https.onRequest((req, res) =>{
var mailOptions={
to: 'receiver#gmail.com',
subject: 'Test Mail',
html: 'Testing the Mail'
}
transporter.sendMail(mailOptions,function(err,response){
if(err){
res.end('Mail not sent');
}
else{
res.end('Mail sent');
}
});
});
Now when you want to send a message, you can use this url: https://us-central1-<project-id>.cloudfunctions.net/sendMail
Replace <project-id> with your Firebase Project ID.