Exim: The Mail Transfer Agent (Paperback)

Preface

Chapter 1. Introduction

Chapter 2. How Internet Mail Works
Different Types of MTA
Internet Message Standards
RFC 822 Message Format
The Message ``On the Wire''
Summary of the SMTP Protocol
Forgery
Authentication and Encryption
Routing a Message
Checking Incoming Mail
Overview of the DNS
DNS Records Used for Mail Routing
Related DNS Records
Common DNS Errors
Role of the Postmaster

Chapter 3. Exim Overview
Exim Philosophy
Exim's Queue
Receiving and Delivering Messages
Exim Processes
Coordination Between Processes
How Exim Is Configured
How Exim Delivers Messages
Local and Remote Addresses
Processing an Address
A Simple Example
Complications While Directing and Routing
Complications During Delivery
Complications After Delivery
Use of Transports by Directors and Routers

Chapter 4. Exim Operations Overview
How Exim Identifies Messages
Watching Exim at Work
The Runtime Configuration File
The Default Qualification Domain
Handling Frozen Bounce Messages
Reducing Activity at High Load
Limiting Message Sizes
Parallel Remote Delivery
Controlling the Number of Delivery Processes
Large Message Queues
Large Installations

Chapter 5. Extending the Delivery Configuration
Multiple Local Domains
Virtual Domains
Mailing Lists
Using an External Local Delivery Agent
Multiple User Addresses
Mixed Local/Remote Domains
Delivering to UUCP
Ignoring the Local Part in Local Deliveries
Handling Local Parts in a Case-Sensitive Manner
Scanning Messages for Viruses
Modifying Message Bodies

Chapter 6. Options Common to Directors and Routers
Conditional Running of Routers and Directors
Changing a Driver's Successful Outcome
Adding Data for Use by Transports
Debugging Directors and Routers
Summary of Director/Router Generic Options

Chapter 7. The Directors
Conditional Running of Directors
Optimizing Single-Level Aliasing
Adding Data for Use by Transports
The aliasfile and forwardfile Directors
The aliasfile Director
The forwardfile Director
The localuser Director
The smartuser Director

Chapter 8. The Routers
Timeouts While Routing
Domains That Route to the Local Host
The lookuphost Router
The domainlist Router
The ipliteral Router
The queryprogram Router

Chapter 9. The Transports
Options Common to All Transports
The smtp Transport
Environment for Local Transports
Options Common to the appendfile and pipe Transports
The appendfile Transport
The pipe Transport
The lmtp Transport
The autoreply Transport

Chapter 10. Message Filtering
Examples of Filter Commands
Filtering Compared with an External Delivery Agent
Setting Up a User Filter
Setting Up a System Filter
Testing Filter Files
Format of Filter Files
Significant Actions
Filter Commands
The add Command
Delivery Commands
Mail Commands
Logging Commands
The testprint Command
The finish Command
Obeying Filter Commands Conditionally
Additional Features for System Filters

Chapter 11. Shared Data and Exim Processes
Message Files
Locking Message Files
Hints Files
Log Files
User and Group IDs for Exim Processes
Process Relationships
The Daemon Process
Reception Processes
Queue Runner Processes
Delivery Processes
Summary of Message Handling Process Types
Other Types of Process

Chapter 12. Delivery Errors and Retrying
Retrying After Errors
Remote Delivery Errors
Local Delivery Errors
Routing and Directing Errors
Retry Rules
Computing Retry Times
Using Retry Times
Retry Rule Examples
Timeout of Retry Data
Long-Term Failures
Ultimate Address Timeout
Intermittently Connected Hosts

Chapter 13. Message Reception and Policy Controls
Message Sources
Message Size Control
Messages from Local Processes
Unqualified Addresses from Remote Hosts
Checking a Remote Host
Checking Remote Sender Addresses
Checking Recipient Addresses
Checking Header Line Syntax
Relay Control
Customizing Prohibition Messages
Incoming Message Processing

Chapter 14. Rewriting Addresses
Automatic Rewriting
Configured Rewriting
Rewriting Rules
Rewriting Patterns
Rewriting Flags
A Further Rewriting Example
Testing Rewriting Rules

Chapter 15. Authentication, Encryption, and Other SMTP Processing
SMTP Authentication
Encrypted SMTP Connections
SMTP over TCP/IP
Local SMTP
Batched SMTP

Chapter 16. File and Database Lookups
Single-Key Lookup Types
Query-Style Lookup Types
Quoting Lookup Data
NIS+
LDAP
MySQL and PostgreSQL
DNS Lookups
Implicit Keys in Query-Style Lookups
Temporary Errors in Lookups
Default Values in Single-Key Lookups
Partial Matching in Single-Key Lookups
Lookup Caching

Chapter 17. String Expansion
Variable Substitution
Header Insertion
Operations on Substrings
Character Translation
Text Substitution
Conditional Expansion
Lookups in Expansion Strings
Extracting Fields from Substrings
IP Address Masking
Quoting
Reexpansion
Running Embedded Perl
Testing String Expansions

Chapter 18. Domain, Host, and Address Lists
Negative Items in Lists
List Items in Files
Lookup Items in Lists
Domain Lists
Host Lists
Address Lists

Chapter 19. Miscellany
Security Issues
Privileged Users
RFC Conformance
Timestamps
Checking Spool Space
Control of DNS Lookups
Bounce Message Handling
Miscellaneous Controls

Chapter 20. Command-Line Interface to Exim
Input Mode Control
Additional Message Data
Immediate Delivery Control
Error Routing
Queue Runner Processes
Configuration Overrides
Watching Exim's Queue
Message Control
Testing Options
Options for Debugging
Terminating the Options
Embedded Perl Options
Compatibility with Sendmail
Calling Exim by Different Names

Chapter 21. Administering Exim
Log Files
Log Destination Control
Format of Main Log Entries
Cycling Log Files
Extracting Information from Log Files
Watching What Exim is Doing
The Exim Monitor
Maintaining Alias and Other Datafiles
Hints Database Maintenance
Mailbox Maintenance

Chapter 22. Building and Installing Exim
Prerequisites
Fetching and Unpacking the Source
Configuration for Building
The Building Process
Installing Exim
Testing Before Turning On
Turning Exim On
Installing Documentation in Info Format
Upgrading to a New Release

Appendix A. Summary of String Expansion

Appendix B. Regular Expressions

Index