Mixed message header attribute in_reply_to "unified" #26

src/Header.php

@@ -139,6 +139,9 @@ protected function parse(){
  if (property_exists($header, 'subject')) {
  $this->attributes["subject"] = $this->decode($header->subject);
  }
+ if (property_exists($header, 'in_reply_to')) {
+ $this->attributes["in_reply_to"] = is_array($header->in_reply_to) ? $header->in_reply_to : [$header->in_reply_to];
+ }
  if (property_exists($header, 'references')) {
  $this->attributes["references"] = $this->decode($header->references);
  }
@@ -458,7 +461,7 @@ private function decodeAddresses($values) {
  * @param object $header
  */
  private function extractAddresses($header) {
- foreach(['from', 'to', 'cc', 'bcc', 'reply_to', 'sender', 'in_reply_to'] as $key){
+ foreach(['from', 'to', 'cc', 'bcc', 'reply_to', 'sender'] as $key){
  if (property_exists($header, $key)) {
  $this->attributes[$key] = $this->parseAddresses($header->$key);
  }