The POPular Manual

Jochen Topf

POPular is a suite of programs for running large mail storage servers with POP3 access.

Table of Contents

Introduction

Features
Definitions

1. The POPular system architecture

Overview
The sequence of events in a POP session

2. Installation of the POPular system

Packages
Compilation
Common setup for proxy and storage server
Setting up the proxy server
Setting up the storage server

3. Configuring pproxy

Command line options

Runtime configuration

The show and set commands
The shutdown command
The capa command
The debug command
The vserv command
The backend command
The pdm command
The prng command

4. Configuring pserv

Starting pserv

Runtime configuration

The show and set commands
The server command
The shutdown command
The capa command
The debug command

5. Configuring pcheckd

Command line options
Signals

6. POPular Database Modules (PDM)

Introduction
Any module (libpdm_any.so)
Master password module (libpdm_master.so)
Berkeley DB Version 2 module (libpdm_db2.so)
Berkeley DB Version 3 module (libpdm_db3.so)
CDB (constant data base) module (libpdm_cdb.so)

7. Logfiles

Logfile format
Log levels
Reopening log files
Max session/load warnings

8. Displaying state of running servers

9. Utility programs

Mail delivery
Cleanup

10. Security

SSL/TLS support
Usage of the user 'root'
Input checks
Using chroot

11. Standards compliance

12. Internals

The extended Maildir format
The XPOP protocol
The MAILCHECK protocol
Mailbox locking
TCP keepalive option
POP3 extensions and capabilities

13. POPular system design issues

High availability issues
Mailbox directory layout
Performance tuning
Using virtual servers

A. Man pages of POPular commands

pcheck -- popcheck client
pcheckd -- Checks for mail in maildir mailboxes
pclean -- Script for periodic cleanup jobs
pcontrol -- Send commands to running pproxy or pserv
pdeliver -- Deliver mail into a maildir mailbox
pproxy -- A POP3 proxy server
pserv -- A POP3 server
pstatus -- Display status of POPular proxy and server
ptestpdm -- Test POPular Database Modules (PDMs)
ringd -- Server for binding low TCP ports from non-root programs

B. The PDM C API

C. Copyright

List of Figures
1. The basic POPular architecture.
1-1. One POP3 server
1-2. More POP3 servers
1-3. Using a POP3 proxy
1-4. The final picture
1-5. New connection and authentication
1-6. Checking mailbox
1-7. Connection to a POP3 server
1-8. Connection to a POPular server
1-9. Proxying between client and backend server
1-10. Empty mailbox
7-1. The three states for logging of load and session limits

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		Introduction