title: php mail not working on rackspace cloud
body: <p>i have this rackspace server, and i installed sendmail there. the sendmail is configured to send emails using  sendgrid. </p>
  
  <p>so the sendmail works via the terminal, but the php mail function returns false, and doesnt send any emails. the sendmail path is correctly set in the php.ini too.</p>
  
  <p>I have this in the /etc/php.ini,</p>
  
  <pre><code>sendmail_path = /usr/sbin/sendmail
  </code></pre>
  
  <p>when i take a phpinfo() using</p>
  
  <pre><code>&lt;?php
  
  phpinfo()
  </code></pre>
  
  <p>it returns </p>
  
  <pre><code>sendmail_path = /usr/sbin/sendmail 
  </code></pre>