title: Connection Timeout on aws when Telnet on Port 25
body: <p>Thanks you for your time.</p>
  
  <p>I have just set up a Postfix mail server which is running as MTA in one of my aws instances. I can successfully connect to the localhost through 'telnet localhost 25', and I can send emails to both external and internal email accounts when connected on localhost, however whenever I try to connect through 'telnet zwitch.it 25' or 'telnet mail.zwitch.it 25' I get a connection timeout.</p>
  
  <p>I have set up all my records, including the MX record and the SPF record with the values "v=spf1 include:amazonses.com include:zwitch.it -all" and "spf2.0/pra include:amazonses.com include:zwitch.it ~all".</p>
  
  <p>I really cannot find what is the problem here, if there is a firewall, or if the port is blocked, or maybe something is wrong with my postfix configuration... I would really appreciate if you could help me.</p>
  
  <p>To set up my postfix mail server I followed the instructions at <a href="http://flurdy.com/docs/postfix/" rel="nofollow">http://flurdy.com/docs/postfix/</a> where it mentions the installation of a simple postfix server.</p>
  
  <p>I thank you in advance for the help.</p>
  
  <p>EDIT: 
  Thanks to the answer below the problem was fixed. I only had to go on my aws security groups and add SMTP to the list!</p>