title: how to send email from web app with mail() in php on CentOS (sendmail, postfix, ...?)
body: <p>We are building a web app and will need to send emails on a frequent basis using php's mail() function. We are using it to send mails when e.g. a user signs up for the app, when a client has a new product order, and so on.</p>
  
  <p>What do we install best on our CentOS server to make this happen? I've read a lot about sendmail vs. postfix vs. other packages to use as an MTA but couldn't figure out what I need.</p>
  
  <p>We will not run mail boxes for our users, we only want to send out email from our web app, not receive any emails (we are using google apps for that)</p>
  
  <p>We are looking for a solutions that is easy to setup and maintain</p>