title: Returning multiple messages in node-red function
body: <p>I'm parsing a json object in a node-red function. The results are between 0 and 30 msg.payloads, which are returned as an array from the function.
  These messages are send to a mqtt node for further processing. It seems that the mqtt node (or the broker) are overwhelmed by 30 payloads in one shot, since not all values are coming through.</p>
  
  <p>Is there a way to delay sending multiple payloads, i.e.</p>
  
  <p>send payload 1</p>
  
  <p>wait 1s</p>
  
  <p>send payload 2</p>
  
  <p>wait 1s</p>
  
  <p>etc</p>
  
  <p>Many thanks in advance.</p>