Nodejs sending email doesnt work from iphone browser

I am using the nodemailer module here: https://github.com/andris9/Nodemailer in order to send an email automatically from a webapp. Having tested it with a PC browser using firefox, everything seems to work fine. However, when I am using an iphone safari to use the app it does not seem to send the email. Ive been scratching my head forever on this and I would be very grateful if anyone knew what was the reason for this!! Note I am using the gmail service, but I have set my gmail so that it sends the message as another address (in this case xyz@abc.com). My code is as follows below:

emailer module:

var nodemailer = require("nodemailer");

function sendEmail(firstname, email){
    var smtpTransport = nodemailer.createTransport("SMTP",{
    service: "Gmail",
    auth: {
            user: "user@gmail.com",
        pass: "mypassword"
     }
    });

smtpTransport.sendMail({
from: "Sender <xyz@abc.com>",
to: email,
subject: "blahblah",
text: "blah blah blah",
}, function(error, response){
if(error){
    console.log(error);
} else{
    console.log("Success!");
}
});
}

exports.sendEmail = sendEmail;

app module:

var express = require("express");
var fs = require("fs");
var clientEmail = require("./clientEmail.js");
var profileEmail = require("./profileEmail.js");

var app = express();
app.use('/css', express.static(__dirname + '/css'));
app.use('/img', express.static(__dirname + '/img'));
app.use('/javascript', express.static(__dirname + '/javascript'));
app.use(express.bodyParser());

var buf = fs.readFileSync("html/index.html");
var index = buf.toString();

app.get('/', function(request, response) {
    response.send(index);
});

app.post('/', function(request, response){
    var email = request.body.email;
    var name = request.body.name;
    var firstname = request.body.firstname;

    clientEmail.sendEmail(firstname,email);
    response.redirect('/');
});

var port = process.env.PORT || 5000;
app.listen(port, function() {
    console.log("Listening on " + port);
});