title: How to correctly set up a cron job that runs a PHP script which sends an email?
body: <p>I've put together a PHP script that sends some content to a predefined email address and wanted to set up a cron job that would run that PHP script each day. Additionally, I've set it up to also send me an email each time the cron runs. 
  I should mention that this script uses the PHP <code>mail()</code> function to send the email in html format and that I've tested if the script works by accessing directly through my browser's address bar.</p>
  
  <p>The cron command:  <code>php /home/myuserid/public_html/projects/jobs/index.php</code></p>
  
  <p>Surprisingly, when the cron ran, I received the following error message through email:</p>
  
  <p><em><strong>Use of uninitialized value in concatenation (.) or string at /usr/bin/sendmail line 15.
  Content-type: text/html</em></strong></p>
  
  <p>I'm not even sure where to start looking for the problem, so I need to ask: how do I correctly set up a simple cron job that runs a PHP scripts which sends an email using the <code>mail()</code> function?</p>