Table of Contents for
Postfix: The Definitive Guide

Version ebook / Retour

Cover image for bash Cookbook, 2nd Edition Postfix: The Definitive Guide by Kyle D. Dent Published by O'Reilly Media, Inc., 2003
  1. Postfix: The Definitive Guide
  2. Cover
  3. Postfix: The Definitive Guide
  4. Foreword
  5. Preface
  6. Audience
  7. Organization
  8. Conventions Used in This Book
  9. Comments and Questions
  10. Acknowledgments
  11. 1. Introduction
  12. 1.1. Postfix Origins and Philosophy
  13. 1.2. Email and the Internet
  14. 1.3. The Role of Postfix
  15. 1.4. Postfix Security
  16. 1.5. Additional Information and How to Obtain Postfix
  17. 2. Prerequisites
  18. 2.1. Unix Topics
  19. 2.2. Email Topics
  20. 3. Postfix Architecture
  21. 3.1. Postfix Components
  22. 3.2. How Messages Enter the Postfix System
  23. 3.3. The Postfix Queue
  24. 3.4. Mail Delivery
  25. 3.5. Tracing a Message Through Postfix
  26. 4. General Configuration and Administration
  27. 4.1. Starting Postfix the First Time
  28. 4.2. Configuration Files
  29. 4.3. Important Configuration Considerations
  30. 4.4. Administration
  31. 4.5. master.cf
  32. 4.6. Receiving Limits
  33. 4.7. Rewriting Addresses
  34. 4.8. chroot
  35. 4.9. Documentation
  36. 5. Queue Management
  37. 5.1. How qmgr Works
  38. 5.2. Queue Tools
  39. 6. Email and DNS
  40. 6.1. DNS Overview
  41. 6.2. Email Routing
  42. 6.3. Postfix and DNS
  43. 6.4. Common Problems
  44. 7. Local Delivery and POP/IMAP
  45. 7.1. Postfix Delivery Transports
  46. 7.2. Message Store Formats
  47. 7.3. Local Delivery
  48. 7.4. POP and IMAP
  49. 7.5. Local Mail Transfer Protocol
  50. 8. Hosting Multiple Domains
  51. 8.1. Shared Domains with System Accounts
  52. 8.2. Separate Domains with System Accounts
  53. 8.3. Separate Domains with Virtual Accounts
  54. 8.4. Separate Message Store
  55. 8.5. Delivery to Commands
  56. 9. Mail Relaying
  57. 9.1. Backup MX
  58. 9.2. Transport Maps
  59. 9.3. Inbound Mail Gateway
  60. 9.4. Outbound Mail Relay
  61. 9.5. UUCP, Fax, and Other Deliveries
  62. 10. Mailing Lists
  63. 10.1. Simple Mailing Lists
  64. 10.2. Mailing-List Managers
  65. 11. Blocking Unsolicited Bulk Email
  66. 11.1. The Nature of Spam
  67. 11.2. The Problem of Spam
  68. 11.3. Open Relays
  69. 11.4. Spam Detection
  70. 11.5. Anti-Spam Actions
  71. 11.6. Postfix Configuration
  72. 11.7. Client-Detection Rules
  73. 11.8. Strict Syntax Parameters
  74. 11.9. Content-Checking
  75. 11.10. Customized Restriction Classes
  76. 11.11. Postfix Anti-Spam Example
  77. 12. SASL Authentication
  78. 12.1. SASL Overview
  79. 12.2. Postfix and SASL
  80. 12.3. Configuring Postfix for SASL
  81. 12.4. Testing Your Authentication Configuration
  82. 12.5. SMTP Client Authentication
  83. 13. Transport Layer Security
  84. 13.1. Postfix and TLS
  85. 13.2. TLS Certificates
  86. 14. Content Filtering
  87. 14.1. Command-Based Filtering
  88. 14.2. Daemon-Based Filtering
  89. 14.3. Other Considerations
  90. 15. External Databases
  91. 15.1. MySQL
  92. 15.2. LDAP
  93. A. Configuration Parameters
  94. A.1. Postfix Parameter Reference
  95. 2bounce_notice_recipient
  96. access_map_reject_code
  97. alias_maps
  98. allow_mail_to_files
  99. allow_percent_hack
  100. alternate_config_directories
  101. append_at_myorigin
  102. authorized_verp_clients
  103. berkeley_db_read_buffer_size
  104. biff
  105. body_checks_size_limit
  106. bounce_service_name
  107. canonical_maps
  108. command_directory
  109. command_time_limit
  110. content_filter
  111. daemon_timeout
  112. debug_peer_list
  113. default_destination_concurrency_limit
  114. default_extra_recipient_limit
  115. default_process_limit
  116. default_recipient_limit
  117. default_verp_delimiters
  118. defer_service_name
  119. delay_notice_recipient
  120. deliver_lock_attempts
  121. disable_dns_lookups
  122. disable_mime_output_conversion
  123. disable_vrfy_command
  124. double_bounce_sender
  125. empty_address_recipient
  126. error_service_name
  127. export_environment
  128. fallback_relay
  129. fast_flush_domains
  130. fast_flush_refresh_time
  131. fork_attempts
  132. forward_expansion_filter
  133. hash_queue_depth
  134. header_address_token_limit
  135. header_size_limit
  136. home_mailbox
  137. ignore_mx_lookup_error
  138. in_flow_delay
  139. initial_destination_concurrency
  140. ipc_idle
  141. line_length_limit
  142. lmtp_connect_timeout
  143. lmtp_data_init_timeout
  144. lmtp_lhlo_timeout
  145. lmtp_quit_timeout
  146. lmtp_rset_timeout
  147. lmtp_tcp_port
  148. local_destination_concurrency_limit
  149. local_recipient_maps
  150. luser_relay
  151. mail_owner
  152. mail_spool_directory
  153. mailbox_command
  154. mailbox_delivery_lock
  155. mailbox_transport
  156. manpage_directory
  157. masquerade_domains
  158. max_idle
  159. maximal_backoff_time
  160. message_size_limit
  161. mime_header_checks
  162. minimal_backoff_time
  163. mydomain
  164. mynetworks
  165. myorigin
  166. newaliases_path
  167. notify_classes
  168. parent_domain_matches_subdomains
  169. pickup_service_name
  170. process_id_directory
  171. proxy_interfaces
  172. qmgr_clog_warn_time
  173. qmgr_message_active_limit
  174. qmgr_message_recipient_minimum
  175. qmqpd_error_delay
  176. queue_directory
  177. queue_run_delay
  178. rbl_reply_maps
  179. recipient_canonical_maps
  180. reject_code
  181. relay_domains_reject_code
  182. relay_transport
  183. relocated_maps
  184. resolve_dequoted_address
  185. sample_directory
  186. sendmail_path
  187. setgid_group
  188. showq_service_name
  189. smtp_bind_address
  190. smtp_data_done_timeout
  191. smtp_data_xfer_timeout
  192. smtp_destination_recipient_limit
  193. smtp_helo_timeout
  194. smtp_mail_timeout
  195. smtp_pix_workaround_delay_time
  196. smtp_quit_timeout
  197. smtp_rcpt_timeout
  198. smtp_skip_5xx_greeting
  199. smtpd_banner
  200. smtpd_data_restrictions
  201. smtpd_error_sleep_time
  202. smtpd_expansion_filter
  203. smtpd_helo_required
  204. smtpd_history_flush_threshold
  205. smtpd_noop_commands
  206. smtpd_recipient_limit
  207. smtpd_restriction_classes
  208. smtpd_soft_error_limit
  209. soft_bounce
  210. strict_7bit_headers
  211. strict_8bitmime_body
  212. strict_rfc821_envelopes
  213. swap_bangpath
  214. syslog_name
  215. transport_retry_time
  216. undisclosed_recipients_header
  217. unknown_client_reject_code
  218. unknown_local_recipient_reject_code
  219. unknown_virtual_alias_reject_code
  220. verp_delimiter_filter
  221. virtual_alias_maps
  222. virtual_mailbox_base
  223. virtual_mailbox_limit
  224. virtual_mailbox_maps
  225. virtual_transport
  226. B. Postfix Commands
  227. C. Compiling and Installing Postfix
  228. C.1. Obtaining Postfix
  229. C.2. Postfix Compiling Primer
  230. C.3. Building Postfix
  231. C.4. Installation
  232. C.5. Compiling Add-on Packages
  233. C.6. Common Problems
  234. C.7. Wrapping Things Up
  235. D. Frequently Asked Questions
  236. Index
  237. About the Author
  238. Colophon
  239. Copyright

Chapter 8. Hosting Multiple Domains

It is very common these days for a single system to host many domains. For instance, http://oreillynet.com and http://onlamp.com might run on a single host, but act as if they were two totally different hosts. A system usually has a canonical domain, which is considered its usual or common domain name. Additional domains are configured as virtual domains. Each virtual domain can host services such as web sites and email as if it were the only domain on a server. This chapter explains several different mechanisms for hosting multiple domains. The techniques are explained separately, but it is possible to mix techniques if you must handle different domains in different ways.

To determine which technique or techniques you need, you must decide how Postfix should deliver messages for virtual domains. There are two important considerations that influence how you should configure Postfix for hosting multiple domains:

  • Should your domains have separate namespaces? For example, should mail for the two addresses and go to the same mailbox or separate ones? We’ll refer to the same mailbox scenario as shared domains, and the other as separate domains.

  • Does every user require a system account? We’ll make the distinction between system accounts that are real Unix accounts on your system and virtual accounts. With virtual accounts, users can have mailboxes on your server, but don’t otherwise log in to the system and don’t require an entry in /etc/passwd.

We’ll consider four different ways Postfix can handle mail for virtual domains:

  • Shared domains with system accounts

  • Separate domains with system accounts

  • Separate domains with virtual accounts

  • Virtual domains with a proprietary message store not managed by Postfix

Your POP/IMAP server will be a major factor in deciding which technique you need. If your POP/IMAP server does not understand virtual domains, then it will most likely require that you have system accounts for all addresses. Some POP/IMAP servers inherently support multiple domains, and deliver messages into a particular directory structure on the local filesystem. Other POP/IMAP servers use their own proprietary message store. Postfix can hand off messages to them using LMTP.

Regardless of the technique you use, all of your virtual domains must be configured correctly in DNS. You should configure DNS for virtual domains the same way you do for your system’s canonical domain. See Chapter 6 for information on Postfix and DNS.