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PCMAIL: A distributed mail system for personal computers (RFC0984)

IP.com Disclosure Number: IPCOM000004982D
Original Publication Date: 1986-May-01
Included in the Prior Art Database: 2001-Jul-13
Document File: 32 page(s) / 68K

Publishing Venue

Internet Society Requests For Comment (RFCs)

Related People

D.D. Clark: AUTHOR [+2]

Abstract

Pcmail is a distributed mail system that provides mail service to an arbitrary number of users, each of which owns one or more personal computers (PCs). The system is divided into two halves. The first consists of a single entity called the "repository". The repository is a storage center for incoming mail. Mail for a Pcmail user can arrive externally from the Internet or internally from other repository users. The repository also maintains a stable copy of each user's mail state (this will hereafter be referred to as the user's "global mail state"). The repository is therefore typically a computer with a large amount of disk storage.

This text was extracted from a ASCII document.
This is the abbreviated version, containing approximately 5% of the total text.

Network Working Group David D. Clark Request for Comments: 984 Mark L. Lambert M. I. T. Laboratory for Computer Science

May 1986

PCMAIL: A Distributed Mail System for Personal Computers

1. Status of this Document

This document is a preliminary discussion of the design of a personal-computer-based distributed mail system. It is published for discussion and comment, and does not constitute a standard. As the proposal may change, implementation of this document is not advised. Distribution of this memo is unlimited.

2. Introduction

Pcmail is a distributed mail system that provides mail service to an arbitrary number of users, each of which owns one or more personal computers (PCs). The system is divided into two halves. The first consists of a single entity called the "repository". The repository is a storage center for incoming mail. Mail for a Pcmail user can arrive externally from the Internet or internally from other repository users. The repository also maintains a stable copy of each user's mail state (this will hereafter be referred to as the user's "global mail state"). The repository is therefore typically a computer with a large amount of disk storage.

The second half of Pcmail consists of one or more "clients". Each Pcmail user may have an arbitrary number of clients, which are typically PCs. The clients provide a user with a friendly means of accessing the user's global mail state over a network. In order to make the interaction between the repository and a user's clients more efficient, each client maintains a local copy of its user's global mail state, called the "local mail state". Since clients are PCs, they may not always have access to a network (and therefore to the global mail state in the repository). This means that the local and global mail states may not be identical all the time, making synchronization between local and global mail states necessary.

Clients communicate with the repository via the Distributed Mail System Protocol (DMSP); the specification for this protocol appears in appendix A. The repository is therefore a DMSP server in addition to a mail end-site and storage facility. DMSP provides a complete set of mail manipulation operations ("send a message", "delete a message", "print a message", etc.). DMSP also provides special operations to allow easy synchronization between a user's global mail state and his clients' local mail states. Particular attention has been paid to the way in which DMSP operations act on a user's mail state. All DMSP operations are atomic (that is, they are guaranteed

Clark Lambert [Page 1]

RFC 984 May 1986 PCMAIL

either to succeed completely, or fail completely). A client can be abruptly disconnected from the repository without leaving inconsistent or damaged mail states.

Pcmail is a mail system for PCs. Its design has therefore been heavily influenced by several characteristic...