A client MAY retrieve all messages without first requesting message headers. In this case, the server MUST return all of the user's offline messages and also MUST NOT send a flood of offline messages if the user subsequently sends initial presence to the server during this session. That is, the semantics here are the same as for requesting message headers.
@@ -295,7 +291,7 @@This section shows the flow of protocol between client (C:) and server (S:) for the existing (flood) scenario and the improved (POP3-like) scenario.
-The semantics change with POP-like offline message handling, and server behavior changes as well...
-A server MUST NOT deliver a user's offline messages to any JID except one of the user's authorized resources.