The Recipient Notification Agent Submission Protocol is the means by which message stores communicate with recipient notification agents. It shares a common structure and common transport layer requirements with the other IM2000 protocols.
Individual to RNASP are:
With RNASP, the client is the message store, and the server is the recipient notification agent.
RNASP is subject to the common IM2000 PDU rules.
The response that an RNASP server must send to a client in the event of a parsing error or a non-command PDU is a ResponseNull PDU comprising
The response that an RNASP server must send to a client in the event of a timeout is a ResponseNull PDU comprising
This is the ASN.1 definition of RNASP.
RNASP is designed for one basic security model with respect to the communications path.
The communications path between client and server may involve third parties. This will usually be the case, since the message store will have no direct prior relationship with the recipient notification agent.
In this case, the protocol is vulnerable to man-in-the-middle attacks, or to any third party capable of injecting traffic into the session. Therefore, for security, clients and servers in such situations should employ transport-level security measures to encrypt PDUs.
There is one task which an originator MUA can perform using RNASP, which comprises a single transaction:
Submission transactions comprise a single command/response pair. The client sends a CommandNotify PDU containing zero or more notifications, and the server sends a ResponseNotify PDU that (if it does not abort the transaction and does not indicate an error status) indicates that the notifications have been receieved by the server.
Each message notification comprises: