code: function addFromAddress(inboundMessage, outboundMessage) {
    if (inboundMessage && _.has(inboundMessage, 'from')) {
      outboundMessage.recipients = outboundMessage.recipients || [];
  
      outboundMessage.recipients.push(inboundMessage.from);
    }
  
    return outboundMessage;
  }
docs: gets the address that sent the inbound message and adds it as a recipient to the outbound message
  
  @param {InboundMessage} inboundMessage
  @param {OutboundMessage} outboundMessage
  @returns {OutboundMessage} outboundMessage