Network Working Group R. Siemborski Request for Comments: 3656 Carnegie Mellon University Category: Experimental December 2003 The Mailbox Update (MUPDATE) Distributed Mailbox Database Protocol Status of this Memo This memo defines an Experimental Protocol for the Internet community. It does not specify an Internet standard of any kind. Discussion and suggestions for improvement are requested. Distribution of this memo is unlimited. Copyright Notice Copyright (C) The Internet Society (2003). All Rights Reserved. Abstract As the demand for high-performance mail delivery agents increases, it becomes apparent that single-machine solutions are inadequate to the task, both because of capacity limits and that the failure of the single machine means a loss of mail delivery for all users. It is preferable to allow many machines to share the responsibility of mail delivery. The Mailbox Update (MUPDATE) protocol allows a group of Internet Message Access Protocol (IMAP) or Post Office Protocol - Version 3 (POP3) servers to function with a unified mailbox namespace. This document is intended to serve as a reference guide to that protocol. Siemborski Experimental