RFC1939-POP3 Agreement Chinese version

1. Introduction

For smaller nodes on the network, it is impractical to support message transfer systems (MTS). For example, a

Workstations may not have sufficient resources to allow SMTP servers and equivalent local mail delivery systems to stay in order,

and continue to run. Similarly, the cost of connecting a personal computer for a long time on an IP-type network is considerable

(Resources missing from nodes are called "liaisons").

Nonetheless, it is useful to allow management of messages at such a summary point, and these nodes often support a

A user agent to manage messages. To solve this problem, MTS nodes can be supported for these unsupported nodes.

For the message store function. Post Office Protocol-version 3 enables such workstations to be accessed in a more practical way

Store messages stored on the server. Typically, this means that the workstation can get mail from the server, while the server is

It temporarily saves the message.

In the following, the client host refers to a host that utilizes the POP3 service, and the server host refers to a POP3 service

Host.

2. Simple description

This document does not indicate how the client host will send the message to the delivery system. But here's a note: when using

When the user agent needs to send the information to the delivery system, it establishes an SMTP connection on the relay host (these relay hosts can be

POP3 host, or it may not be.

3. Basic operation

Initially, the server starts the POP3 service by listening on TCP port 110. When a client host needs to use a service, it

Establish a TCP connection to the server host. When the connection is established, POP3 sends a confirmation message. Customer and POP3 servers are each other (divided

Do not exchange commands and responses, this process continues until the connection terminates.

The POP3 command consists of a command and some parameters. All commands with a CRLF to the end. Commands and parameters can be hit by

Printed ASCII characters that are spaced between spaces. Commands are typically three to four letters, each with a parameter of up to 40