title: Send emails from AWS EC2 instance (SES mandatory?)
body: <p>I write this post just to see if I can get some clarifications regarding email sending concepts in an AWS EC2 instance.</p>
  
  <p>This is related with this other post <a href="https://stackoverflow.com/questions/23814906/rails-does-not-send-emails-on-aws/23817424?noredirect=1#23817424">Rails does not send emails on AWS</a> </p>
  
  <p>I´m developing a Rails application that sends emails to customers (such as confirmation or information emails). </p>
  
  <p>I dont know exactly which email service is using Rails. I didn´t install any particular gem. But the emails are been sent perfectly in development environment (Ubuntu).</p>
  
  <p>When I deploy to my production environment (AWS EC2 instance). This functionality is not working. You can see the error details in the post I provided above. The error is related with some <code>smtp connection refused</code>.</p>
  
  <p>So, I have read some other posts but Im confused. Is it mandatory to use the AWS SES service in order to send emails from EC2 instance? Or it is just a problem related to security credentials (maybe I just need to open the smtp 25 port). Do I need to install any email client or server?</p>