title: How do I save changes to a file edited in Terminal on OS X Yosemite?
body: <p>I'm following this tutorial to get my postfix working with mamp pro. 
  <a href="http://macnevada.net/mamp-pro-3-06-postfix-smart-host-not-working-on-osx-yosemite/" rel="nofollow">http://macnevada.net/mamp-pro-3-06-postfix-smart-host-not-working-on-osx-yosemite/</a></p>
  
  <p>I've been following along well, but I'm at the part where I need to save the changes I made to the main.cf file in the terminal. I'm pretty new to the terminal. So how do I save the file?</p>