MailMessage: ensure encoding is set for empty messages

Author: glensc

src/Mail/MailMessage.php

@@ -53,6 +53,8 @@
  */
 class MailMessage extends Message
 {
+    const ENCODING = APP_CHARSET;
+
     /** @var Attachment */
     private $attachment;
 
@@ -81,6 +83,9 @@ public static function createNew()
     {
         $message = new self(['root' => true]);
 
+        // ensure encoding is set
+        $message->getHeaders()->setEncoding(self::ENCODING);
+
         return $message;
     }