Table of Contents for
Postfix: The Definitive Guide
Postfix: The Definitive Guide
Published by
O'Reilly Media, Inc., 2003
- Postfix: The Definitive Guide
- Cover
- Postfix: The Definitive Guide
- Foreword
- Preface
- Audience
- Organization
- Conventions Used in This Book
- Comments and Questions
- Acknowledgments
- 1. Introduction
- 1.1. Postfix Origins and Philosophy
- 1.2. Email and the Internet
- 1.3. The Role of Postfix
- 1.4. Postfix Security
- 1.5. Additional Information and How to Obtain Postfix
- 2. Prerequisites
- 2.1. Unix Topics
- 2.2. Email Topics
- 3. Postfix Architecture
- 3.1. Postfix Components
- 3.2. How Messages Enter the Postfix System
- 3.3. The Postfix Queue
- 3.4. Mail Delivery
- 3.5. Tracing a Message Through Postfix
- 4. General Configuration and Administration
- 4.1. Starting Postfix the First Time
- 4.2. Configuration Files
- 4.3. Important Configuration Considerations
- 4.4. Administration
- 4.5. master.cf
- 4.6. Receiving Limits
- 4.7. Rewriting Addresses
- 4.8. chroot
- 4.9. Documentation
- 5. Queue Management
- 5.1. How qmgr Works
- 5.2. Queue Tools
- 6. Email and DNS
- 6.1. DNS Overview
- 6.2. Email Routing
- 6.3. Postfix and DNS
- 6.4. Common Problems
- 7. Local Delivery and POP/IMAP
- 7.1. Postfix Delivery Transports
- 7.2. Message Store Formats
- 7.3. Local Delivery
- 7.4. POP and IMAP
- 7.5. Local Mail Transfer Protocol
- 8. Hosting Multiple Domains
- 8.1. Shared Domains with System Accounts
- 8.2. Separate Domains with System Accounts
- 8.3. Separate Domains with Virtual Accounts
- 8.4. Separate Message Store
- 8.5. Delivery to Commands
- 9. Mail Relaying
- 9.1. Backup MX
- 9.2. Transport Maps
- 9.3. Inbound Mail Gateway
- 9.4. Outbound Mail Relay
- 9.5. UUCP, Fax, and Other Deliveries
- 10. Mailing Lists
- 10.1. Simple Mailing Lists
- 10.2. Mailing-List Managers
- 11. Blocking Unsolicited Bulk Email
- 11.1. The Nature of Spam
- 11.2. The Problem of Spam
- 11.3. Open Relays
- 11.4. Spam Detection
- 11.5. Anti-Spam Actions
- 11.6. Postfix Configuration
- 11.7. Client-Detection Rules
- 11.8. Strict Syntax Parameters
- 11.9. Content-Checking
- 11.10. Customized Restriction Classes
- 11.11. Postfix Anti-Spam Example
- 12. SASL Authentication
- 12.1. SASL Overview
- 12.2. Postfix and SASL
- 12.3. Configuring Postfix for SASL
- 12.4. Testing Your Authentication Configuration
- 12.5. SMTP Client Authentication
- 13. Transport Layer Security
- 13.1. Postfix and TLS
- 13.2. TLS Certificates
- 14. Content Filtering
- 14.1. Command-Based Filtering
- 14.2. Daemon-Based Filtering
- 14.3. Other Considerations
- 15. External Databases
- 15.1. MySQL
- 15.2. LDAP
- A. Configuration Parameters
- A.1. Postfix Parameter Reference
- 2bounce_notice_recipient
- access_map_reject_code
- alias_maps
- allow_mail_to_files
- allow_percent_hack
- alternate_config_directories
- append_at_myorigin
- authorized_verp_clients
- berkeley_db_read_buffer_size
- biff
- body_checks_size_limit
- bounce_service_name
- canonical_maps
- command_directory
- command_time_limit
- content_filter
- daemon_timeout
- debug_peer_list
- default_destination_concurrency_limit
- default_extra_recipient_limit
- default_process_limit
- default_recipient_limit
- default_verp_delimiters
- defer_service_name
- delay_notice_recipient
- deliver_lock_attempts
- disable_dns_lookups
- disable_mime_output_conversion
- disable_vrfy_command
- double_bounce_sender
- empty_address_recipient
- error_service_name
- export_environment
- fallback_relay
- fast_flush_domains
- fast_flush_refresh_time
- fork_attempts
- forward_expansion_filter
- hash_queue_depth
- header_address_token_limit
- header_size_limit
- home_mailbox
- ignore_mx_lookup_error
- in_flow_delay
- initial_destination_concurrency
- ipc_idle
- line_length_limit
- lmtp_connect_timeout
- lmtp_data_init_timeout
- lmtp_lhlo_timeout
- lmtp_quit_timeout
- lmtp_rset_timeout
- lmtp_tcp_port
- local_destination_concurrency_limit
- local_recipient_maps
- luser_relay
- mail_owner
- mail_spool_directory
- mailbox_command
- mailbox_delivery_lock
- mailbox_transport
- manpage_directory
- masquerade_domains
- max_idle
- maximal_backoff_time
- message_size_limit
- mime_header_checks
- minimal_backoff_time
- mydomain
- mynetworks
- myorigin
- newaliases_path
- notify_classes
- parent_domain_matches_subdomains
- pickup_service_name
- process_id_directory
- proxy_interfaces
- qmgr_clog_warn_time
- qmgr_message_active_limit
- qmgr_message_recipient_minimum
- qmqpd_error_delay
- queue_directory
- queue_run_delay
- rbl_reply_maps
- recipient_canonical_maps
- reject_code
- relay_domains_reject_code
- relay_transport
- relocated_maps
- resolve_dequoted_address
- sample_directory
- sendmail_path
- setgid_group
- showq_service_name
- smtp_bind_address
- smtp_data_done_timeout
- smtp_data_xfer_timeout
- smtp_destination_recipient_limit
- smtp_helo_timeout
- smtp_mail_timeout
- smtp_pix_workaround_delay_time
- smtp_quit_timeout
- smtp_rcpt_timeout
- smtp_skip_5xx_greeting
- smtpd_banner
- smtpd_data_restrictions
- smtpd_error_sleep_time
- smtpd_expansion_filter
- smtpd_helo_required
- smtpd_history_flush_threshold
- smtpd_noop_commands
- smtpd_recipient_limit
- smtpd_restriction_classes
- smtpd_soft_error_limit
- soft_bounce
- strict_7bit_headers
- strict_8bitmime_body
- strict_rfc821_envelopes
- swap_bangpath
- syslog_name
- transport_retry_time
- undisclosed_recipients_header
- unknown_client_reject_code
- unknown_local_recipient_reject_code
- unknown_virtual_alias_reject_code
- verp_delimiter_filter
- virtual_alias_maps
- virtual_mailbox_base
- virtual_mailbox_limit
- virtual_mailbox_maps
- virtual_transport
- B. Postfix Commands
- C. Compiling and Installing Postfix
- C.1. Obtaining Postfix
- C.2. Postfix Compiling Primer
- C.3. Building Postfix
- C.4. Installation
- C.5. Compiling Add-on Packages
- C.6. Common Problems
- C.7. Wrapping Things Up
- D. Frequently Asked Questions
- Index
- About the Author
- Colophon
- Copyright
Postfix Components
The architecture of Postfix is quite different from that
of a monolithic system such as Sendmail, which traditionally uses a
single large program for its handling of email messages. Postfix breaks
down tasks into separate functions using individual programs that each
perform one specific task. Most of these programs are daemons, which are processes that run in the background on
your system. The master daemon is started first, and it invokes most other
processes, as needed. Postfix daemons that are invoked by the master daemon process their assigned tasks and
terminate. They might also terminate after a configured amount of time
or after handling a maximum number of requests. The master daemon is
resident at all times, and gets its configuration information at startup from both main.cf and master.cf. See Chapter 4 for more information on Postfix
configuration files.
Figure 3-1 depicts a high-level picture of the Postfix architecture. Broadly speaking, Postfix receives messages, queues them, and finally delivers them. Each stage of processing is handled by a distinct set of Postfix components. After a message is received and placed into the queue, the queue manager invokes the appropriate delivery agent for the final disposition of the message. The next few sections in this chapter discuss the details of each of the stages.
