Two separate models for conveying instant messages have been defined. Page-mode messages stand alone and are not part of a Session Initiation Protocol (SIP) session@ whereas session-mode messages are set up as part of a session using SIP. The Message Session Relay Protocol (MSRP) is a protocol for near real-time@ peer-to-peer exchanges of binary content without intermediaries@ which is designed to be signaled using a separate rendezvous protocol such as SIP. This document introduces the notion of message relay intermediaries to MSRP and describes the extensions necessary to use them.