title: How can I send emails to multiple recipients using a MailDefinition
body: <p>I'm creating a new mail definition using the <code>CreateMailMessage</code> function of a <code>MailDefinition</code>. One of the required parameters is recipients. The documentation for this function states that recipients is to be a comma-separated list of recipients, however when I try to send a message to multiple users I am getting the following error: </p>
  
  <pre><code>An invalid character was found in the mail header: ','...
  </code></pre>
  
  <p>So it seems like this function is not working as intended. Normally I would add all the recipients to the mail message itself, but unfortunately the recipients parameter is required and cannot be left blank. Any ideas?</p>