Why timeout occurs while sending email using nodemailer when amazon ec2 server is used

Question

I am using nodemailer to send email from ec2 server but it is getting timeout

var nodemailer = require('nodemailer');
var smtpConfig =   {
                     service : 'Gmail',
                     secure : true,
                     auth   : {
                        user: 'adminemail@gmail.com',
                        pass: 'password'
                    }
                };
var smtpTransport  =   nodemailer.createTransport(smtpConfig);

smtpTransport.sendMail({
      from    : '"Admin" < adminemail@gmail.com >',
      to      : 'user@gmail.com',
      subject : 'click on link',
      html    : 'Please click on link'
   }, 
   function(err, res){
            if(err){
                console.log("email send error",err);
            }else{
                console.log("On Email Send Success : ", res);
            }
});

The above code is working fine on localhost but when i tried on live server running on EC2, it is getting timeout

email send error { [Error: Connection timeout] code: 'ETIMEDOUT' }

Please suggest a way to modify the code