Section on Sender Capacity and Replay says:
"A synchronous send call will block until the broker has confirmed receipt of the message." This sounds like the confirmation is received when the broker has received the message on an exchange or you could possibly interpret it as delivered on a queue.
"The sender can be queried for the available space (i.e. the unused capacity), and for the current count of unsettled messages (i.e. those held in the queue pending confirmation by the server). When the unsettled count is zero, all messages on that sender have been successfully sent. "
This makes it sound like confirmations are when a/all receiver(s) has received the messages from a queue.
Are there two confirmations?
It seems this section needs to be more explicit on types of confirmations and confirmation events.
e.g. in some sense there is also the idea of a blocked call when sending (synch or asyn) which is in itself a kind of confirmation. e.g. if I have a successful unblocked send in synch or asynh mode doesn't that imply that the broker has received the message?