Nodemailer not working on Amazon EC2 instance

I am EC2 instance up and running , I wanted to integrate nodemailer in my application. Following the http://ift.tt/1tGxIwu I was able to send email from my localhost. When the same code I integrated on EC2 instance I am getting Invalid login error . Sometime gmail blocks login from other application and send confirm mail to the inbox. I didnt get any such mail also. Do I need to enable some port on EC2 instance or I can use nodemailer at all on EC2 instance. Please suggest