Merge pull request #2617 from vjFaLk/message-id-fix

[fix] add brackets to message-id

frappe/email/email_body.py

@@ -185,7 +185,7 @@ class EMail:
 
 	def set_message_id(self, message_id):
 		if message_id:
-			self.msg_root["Message-Id"] = message_id
+			self.msg_root["Message-Id"] = '<' + message_id + '>'
 		else:
 			self.msg_root["Message-Id"] = get_message_id()
 			self.msg_root["References"] = '<notification>'