Qmail Quickstarter: Install, Set Up and Run your own Email Server电子书

Qmail Quickstarter

Table of Contents

Qmail Quickstarter

Credits

About the Author

About the Reviewer

Preface

What This Book Covers

What You Need for This Book

Who This Book is For

Conventions

Reader Feedback

Customer Support

Downloading the Example Code for the Book

Errata

Questions

1. Basic Qmail

The Minimum Qmail System

Compiling and Installing

Preparing the System

Compiling and Installing the Necessary Binaries

Creating the Basic Configuration Files

Creating the Necessary Minimum Account Aliases

Default Mail Delivery

Basic Configuration

Simple Execution

qmail-start

qmail-smtpd

Administrative Conveniences

About Patches

ucspi-tcp and daemontools

Installation

Using tcpserver

Using svscan

Logging

The Overall Structure of Qmail

Summary

2. Getting Email into the Queue

qmail-queue and the Qmail Queue

The qmail-inject and sendmail Interfaces

qmail-smtpd and the QMAILQUEUE Patch

Accepting or Rejecting Email

RELAYCLIENT and Authentication

tcprules

POP-before-SMTP

SMTP-AUTH

The QMAILQUEUE Patch

Other Mail Protocols

Quick Mail Transfer Protocol (QMTP)

Old-Fashioned Mail Injection Protocol (OFMIP)

Summary

3. Getting Email Out of the Queue

qmail-send and the Qmail Queue

Delivering Email Locally

The Default

.qmail Files

Forwards

Maildirs and mboxes

Pipes and Programs

Supporting .forward Files

Users

The virtualdomains File

Defined Users: The users/assign File

Aliases

Extensions

Delivering Email Remotely

How It Normally Works

Static Routes

Authentication

Summary

4. Storing and Retrieving Email

Popular Storage Formats

Reliability

Speed

Reading

Marking

Deleting

Delivery

Searching

On-Disk Efficiency

The POP3 and IMAP Protocols

Protocol and Server Selection

qmail-pop3d Server Setup

The Checkpassword Interface

Installing the checkpassword Program

Running with tcpserver

Webmail

Summary

5. Virtualization

Generic Virtualization Framework

Power of the virtualdomains File

Basic Virtual Domains

The Path of an Email

Non-Virtual Non-System Users

User-Management Problem in Assisted Virtual Domains

Popular Solutions: vpopmail and VMailMgr

Consequences for Other Services

Good Reasons to Use Multiple Installations

How to Set Up Multiple Qmail Installations

Hiding Multiple Queues from the User

Summary

6. Filtering

Basic Filtering Architecture

Sending Mail Without a Queue

Blocking Viruses

Heavyweight Filtering

Lightweight Filtering

Stopping Spam from Getting In

Sender Validation

SPF

DomainKeys

Identifying Spam

Lightweight

Domain Name System Black-Lists

Checking for SMTP Violations

Pattern Matching

Heavyweight

Bayesian and other Machine-Learning Techniques

Ensemble Identification

Quarantines and Challenges

Mistakes

Stopping Spam from Getting Out

Sender Restrictions

Bounce-Back Spam

Recipient Validation

Recipient Validation is Insufficient

Summary

7. Advanced Features

SSL Encryption

Patch vs. Wrapper

When Receiving Email

When Sending Email

Mailing Lists

Lightweight vs. Heavyweight

Speed vs. Size

Member Management

Efficiency under Load

Variable Envelope Return Path

Integration with Qmail

Web Interface

Summary

8. Administration, Optimization, and Monitoring

The Log Files

The Basic qmail-smtpd Log

Expanding the qmail-smtpd Log

The Basic qmail-send Log

Basic Analysis

qmailanalog

Identifying Problems

Making It Faster

Calculating Your Limits

Finding Bottlenecks

Concurrency

Resource Starvation

DNS

Filesystem

Silly Qmail Syndrome

Summary

Index