1<!doctype html public "-//W3C//DTD HTML 4.01 Transitional//EN" 2 "http://www.w3.org/TR/html4/loose.dtd"> 3<html> <head> 4<meta http-equiv="Content-Type" content="text/html; charset=us-ascii"> 5<title> Postfix manual - virtual(8) </title> 6</head> <body> <pre> 7VIRTUAL(8) VIRTUAL(8) 8 9<b>NAME</b> 10 virtual - Postfix virtual domain mail delivery agent 11 12<b>SYNOPSIS</b> 13 <b>virtual</b> [generic Postfix daemon options] 14 15<b>DESCRIPTION</b> 16 The <a href="virtual.8.html"><b>virtual</b>(8)</a> delivery agent is designed for virtual mail hosting ser- 17 vices. Originally based on the Postfix <a href="local.8.html"><b>local</b>(8)</a> delivery agent, this 18 agent looks up recipients with map lookups of their full recipient 19 address, instead of using hard-coded unix password file lookups of the 20 address local part only. 21 22 This delivery agent only delivers mail. Other features such as mail 23 forwarding, out-of-office notifications, etc., must be configured via 24 virtual_alias maps or via similar lookup mechanisms. 25 26<b>MAILBOX LOCATION</b> 27 The mailbox location is controlled by the <b><a href="postconf.5.html#virtual_mailbox_base">virtual_mailbox_base</a></b> and <b><a href="postconf.5.html#virtual_mailbox_maps">vir</a>-</b> 28 <b><a href="postconf.5.html#virtual_mailbox_maps">tual_mailbox_maps</a></b> configuration parameters (see below). The <b><a href="postconf.5.html#virtual_mailbox_maps">vir-</b> 29 <b>tual_mailbox_maps</a></b> table is indexed by the recipient address as 30 described under TABLE SEARCH ORDER below. 31 32 The mailbox pathname is constructed as follows: 33 34 <b>$<a href="postconf.5.html#virtual_mailbox_base">virtual_mailbox_base</a>/$virtual_mailbox_maps(</b><i>recipient</i><b>)</b> 35 36 where <i>recipient</i> is the full recipient address. 37 38<b>UNIX MAILBOX FORMAT</b> 39 When the mailbox location does not end in <b>/</b>, the message is delivered 40 in UNIX mailbox format. This format stores multiple messages in one 41 textfile. 42 43 The <a href="virtual.8.html"><b>virtual</b>(8)</a> delivery agent prepends a "<b>From</b> <i>sender time</i><b>_</b><i>stamp</i>" enve- 44 lope header to each message, prepends a <b>Delivered-To:</b> message header 45 with the envelope recipient address, prepends an <b>X-Original-To:</b> header 46 with the recipient address as given to Postfix, prepends a <b>Return-Path:</b> 47 message header with the envelope sender address, prepends a > character 48 to lines beginning with "<b>From</b> ", and appends an empty line. 49 50 The mailbox is locked for exclusive access while delivery is in 51 progress. In case of problems, an attempt is made to truncate the mail- 52 box to its original length. 53 54<b>QMAIL MAILDIR FORMAT</b> 55 When the mailbox location ends in <b>/</b>, the message is delivered in qmail 56 <b>maildir</b> format. This format stores one message per file. 57 58 The <a href="virtual.8.html"><b>virtual</b>(8)</a> delivery agent prepends a <b>Delivered-To:</b> message header 59 with the final envelope recipient address, prepends an <b>X-Original-To:</b> 60 header with the recipient address as given to Postfix, and prepends a 61 <b>Return-Path:</b> message header with the envelope sender address. 62 63 By definition, <b>maildir</b> format does not require application-level file 64 locking during mail delivery or retrieval. 65 66<b>MAILBOX OWNERSHIP</b> 67 Mailbox ownership is controlled by the <b><a href="postconf.5.html#virtual_uid_maps">virtual_uid_maps</a></b> and <b><a href="postconf.5.html#virtual_gid_maps">vir</a>-</b> 68 <b><a href="postconf.5.html#virtual_gid_maps">tual_gid_maps</a></b> lookup tables, which are indexed with the full recipient 69 address. Each table provides a string with the numerical user and group 70 ID, respectively. 71 72 The <b><a href="postconf.5.html#virtual_minimum_uid">virtual_minimum_uid</a></b> parameter imposes a lower bound on numerical 73 user ID values that may be specified in any <b><a href="postconf.5.html#virtual_uid_maps">virtual_uid_maps</a></b>. 74 75<b>CASE FOLDING</b> 76 All delivery decisions are made using the full recipient address, 77 folded to lower case. See also the next section for a few exceptions 78 with optional address extensions. 79 80<b>TABLE SEARCH ORDER</b> 81 Normally, a lookup table is specified as a text file that serves as 82 input to the <a href="postmap.1.html"><b>postmap</b>(1)</a> command. The result, an indexed file in <b>dbm</b> or 83 <b>db</b> format, is used for fast searching by the mail system. 84 85 The search order is as follows. The search stops upon the first suc- 86 cessful lookup. 87 88 <b>o</b> When the recipient has an optional address extension the 89 <i>user+extension@domain.tld</i> address is looked up first. 90 91 With Postfix versions before 2.1, the optional address extension 92 is always ignored. 93 94 <b>o</b> The <i>user@domain.tld</i> address, without address extension, is 95 looked up next. 96 97 <b>o</b> Finally, the recipient <i>@domain</i> is looked up. 98 99 When the table is provided via other means such as NIS, LDAP or SQL, 100 the same lookups are done as for ordinary indexed files. 101 102 Alternatively, a table can be provided as a regular-expression map 103 where patterns are given as regular expressions. In that case, only the 104 full recipient address is given to the regular-expression map. 105 106<b>SECURITY</b> 107 The <a href="virtual.8.html"><b>virtual</b>(8)</a> delivery agent is not security sensitive, provided that 108 the lookup tables with recipient user/group ID information are ade- 109 quately protected. This program is not designed to run chrooted. 110 111 The <a href="virtual.8.html"><b>virtual</b>(8)</a> delivery agent disallows regular expression substitution 112 of $1 etc. in regular expression lookup tables, because that would open 113 a security hole. 114 115 The <a href="virtual.8.html"><b>virtual</b>(8)</a> delivery agent will silently ignore requests to use the 116 <a href="proxymap.8.html"><b>proxymap</b>(8)</a> server. Instead it will open the table directly. Before 117 Postfix version 2.2, the virtual delivery agent will terminate with a 118 fatal error. 119 120<b>STANDARDS</b> 121 <a href="http://tools.ietf.org/html/rfc822">RFC 822</a> (ARPA Internet Text Messages) 122 123<b>DIAGNOSTICS</b> 124 Mail bounces when the recipient has no mailbox or when the recipient is 125 over disk quota. In all other cases, mail for an existing recipient is 126 deferred and a warning is logged. 127 128 Problems and transactions are logged to <b>syslogd</b>(8). Corrupted message 129 files are marked so that the queue manager can move them to the <b>corrupt</b> 130 queue afterwards. 131 132 Depending on the setting of the <b><a href="postconf.5.html#notify_classes">notify_classes</a></b> parameter, the postmas- 133 ter is notified of bounces and of other trouble. 134 135<b>BUGS</b> 136 This delivery agent supports address extensions in email addresses and 137 in lookup table keys, but does not propagate address extension informa- 138 tion to the result of table lookup. 139 140 Postfix should have lookup tables that can return multiple result 141 attributes. In order to avoid the inconvenience of maintaining three 142 tables, use an LDAP or MYSQL database. 143 144<b>CONFIGURATION PARAMETERS</b> 145 Changes to <a href="postconf.5.html"><b>main.cf</b></a> are picked up automatically, as <a href="virtual.8.html"><b>virtual</b>(8)</a> processes 146 run for only a limited amount of time. Use the command "<b>postfix reload</b>" 147 to speed up a change. 148 149 The text below provides only a parameter summary. See <a href="postconf.5.html"><b>postconf</b>(5)</a> for 150 more details including examples. 151 152<b>MAILBOX DELIVERY CONTROLS</b> 153 <b><a href="postconf.5.html#virtual_mailbox_base">virtual_mailbox_base</a> (empty)</b> 154 A prefix that the <a href="virtual.8.html"><b>virtual</b>(8)</a> delivery agent prepends to all 155 pathname results from $<a href="postconf.5.html#virtual_mailbox_maps">virtual_mailbox_maps</a> table lookups. 156 157 <b><a href="postconf.5.html#virtual_mailbox_maps">virtual_mailbox_maps</a> (empty)</b> 158 Optional lookup tables with all valid addresses in the domains 159 that match $<a href="postconf.5.html#virtual_mailbox_domains">virtual_mailbox_domains</a>. 160 161 <b><a href="postconf.5.html#virtual_minimum_uid">virtual_minimum_uid</a> (100)</b> 162 The minimum user ID value that the <a href="virtual.8.html"><b>virtual</b>(8)</a> delivery agent 163 accepts as a result from $<a href="postconf.5.html#virtual_uid_maps">virtual_uid_maps</a> table lookup. 164 165 <b><a href="postconf.5.html#virtual_uid_maps">virtual_uid_maps</a> (empty)</b> 166 Lookup tables with the per-recipient user ID that the <a href="virtual.8.html"><b>virtual</b>(8)</a> 167 delivery agent uses while writing to the recipient's mailbox. 168 169 <b><a href="postconf.5.html#virtual_gid_maps">virtual_gid_maps</a> (empty)</b> 170 Lookup tables with the per-recipient group ID for <a href="virtual.8.html"><b>virtual</b>(8)</a> 171 mailbox delivery. 172 173 Available in Postfix version 2.0 and later: 174 175 <b><a href="postconf.5.html#virtual_mailbox_domains">virtual_mailbox_domains</a> ($<a href="postconf.5.html#virtual_mailbox_maps">virtual_mailbox_maps</a>)</b> 176 Postfix is final destination for the specified list of domains; 177 mail is delivered via the $<a href="postconf.5.html#virtual_transport">virtual_transport</a> mail delivery 178 transport. 179 180 <b><a href="postconf.5.html#virtual_transport">virtual_transport</a> (virtual)</b> 181 The default mail delivery transport and next-hop destination for 182 final delivery to domains listed with $<a href="postconf.5.html#virtual_mailbox_domains">virtual_mailbox_domains</a>. 183 184 Available in Postfix version 2.5.3 and later: 185 186 <b><a href="postconf.5.html#strict_mailbox_ownership">strict_mailbox_ownership</a> (yes)</b> 187 Defer delivery when a mailbox file is not owned by its recipi- 188 ent. 189 190<b>LOCKING CONTROLS</b> 191 <b><a href="postconf.5.html#virtual_mailbox_lock">virtual_mailbox_lock</a> (see 'postconf -d' output)</b> 192 How to lock a UNIX-style <a href="virtual.8.html"><b>virtual</b>(8)</a> mailbox before attempting 193 delivery. 194 195 <b><a href="postconf.5.html#deliver_lock_attempts">deliver_lock_attempts</a> (20)</b> 196 The maximal number of attempts to acquire an exclusive lock on a 197 mailbox file or <a href="bounce.8.html"><b>bounce</b>(8)</a> logfile. 198 199 <b><a href="postconf.5.html#deliver_lock_delay">deliver_lock_delay</a> (1s)</b> 200 The time between attempts to acquire an exclusive lock on a 201 mailbox file or <a href="bounce.8.html"><b>bounce</b>(8)</a> logfile. 202 203 <b><a href="postconf.5.html#stale_lock_time">stale_lock_time</a> (500s)</b> 204 The time after which a stale exclusive mailbox lockfile is 205 removed. 206 207<b>RESOURCE AND RATE CONTROLS</b> 208 <b><a href="postconf.5.html#virtual_destination_concurrency_limit">virtual_destination_concurrency_limit</a> ($<a href="postconf.5.html#default_destination_concurrency_limit">default_destination_concur</a>-</b> 209 <b><a href="postconf.5.html#default_destination_concurrency_limit">rency_limit</a>)</b> 210 The maximal number of parallel deliveries to the same destina- 211 tion via the virtual message delivery transport. 212 213 <b><a href="postconf.5.html#virtual_destination_recipient_limit">virtual_destination_recipient_limit</a> ($<a href="postconf.5.html#default_destination_recipient_limit">default_destination_recipi</a>-</b> 214 <b><a href="postconf.5.html#default_destination_recipient_limit">ent_limit</a>)</b> 215 The maximal number of recipients per message for the virtual 216 message delivery transport. 217 218 <b><a href="postconf.5.html#virtual_mailbox_limit">virtual_mailbox_limit</a> (51200000)</b> 219 The maximal size in bytes of an individual <a href="virtual.8.html"><b>virtual</b>(8)</a> mailbox or 220 maildir file, or zero (no limit). 221 222<b>MISCELLANEOUS CONTROLS</b> 223 <b><a href="postconf.5.html#config_directory">config_directory</a> (see 'postconf -d' output)</b> 224 The default location of the Postfix <a href="postconf.5.html">main.cf</a> and <a href="master.5.html">master.cf</a> con- 225 figuration files. 226 227 <b><a href="postconf.5.html#daemon_timeout">daemon_timeout</a> (18000s)</b> 228 How much time a Postfix daemon process may take to handle a 229 request before it is terminated by a built-in watchdog timer. 230 231 <b><a href="postconf.5.html#delay_logging_resolution_limit">delay_logging_resolution_limit</a> (2)</b> 232 The maximal number of digits after the decimal point when log- 233 ging sub-second delay values. 234 235 <b><a href="postconf.5.html#ipc_timeout">ipc_timeout</a> (3600s)</b> 236 The time limit for sending or receiving information over an 237 internal communication channel. 238 239 <b><a href="postconf.5.html#max_idle">max_idle</a> (100s)</b> 240 The maximum amount of time that an idle Postfix daemon process 241 waits for an incoming connection before terminating voluntarily. 242 243 <b><a href="postconf.5.html#max_use">max_use</a> (100)</b> 244 The maximal number of incoming connections that a Postfix daemon 245 process will service before terminating voluntarily. 246 247 <b><a href="postconf.5.html#process_id">process_id</a> (read-only)</b> 248 The process ID of a Postfix command or daemon process. 249 250 <b><a href="postconf.5.html#process_name">process_name</a> (read-only)</b> 251 The process name of a Postfix command or daemon process. 252 253 <b><a href="postconf.5.html#queue_directory">queue_directory</a> (see 'postconf -d' output)</b> 254 The location of the Postfix top-level queue directory. 255 256 <b><a href="postconf.5.html#syslog_facility">syslog_facility</a> (mail)</b> 257 The syslog facility of Postfix logging. 258 259 <b><a href="postconf.5.html#syslog_name">syslog_name</a> (see 'postconf -d' output)</b> 260 The mail system name that is prepended to the process name in 261 syslog records, so that "smtpd" becomes, for example, "post- 262 fix/smtpd". 263 264<b>SEE ALSO</b> 265 <a href="qmgr.8.html">qmgr(8)</a>, queue manager 266 <a href="bounce.8.html">bounce(8)</a>, delivery status reports 267 <a href="postconf.5.html">postconf(5)</a>, configuration parameters 268 syslogd(8), system logging 269 270<b>README_FILES</b> 271 Use "<b>postconf <a href="postconf.5.html#readme_directory">readme_directory</a></b>" or 272 "<b>postconf <a href="postconf.5.html#html_directory">html_directory</a></b>" to locate this information. 273 <a href="VIRTUAL_README.html">VIRTUAL_README</a>, domain hosting howto 274 275<b>LICENSE</b> 276 The Secure Mailer license must be distributed with this software. 277 278<b>HISTORY</b> 279 This delivery agent was originally based on the Postfix local delivery 280 agent. Modifications mainly consisted of removing code that either was 281 not applicable or that was not safe in this context: aliases, 282 ~user/.forward files, delivery to "|command" or to /file/name. 283 284 The <b>Delivered-To:</b> message header appears in the <b>qmail</b> system by Daniel 285 Bernstein. 286 287 The <b>maildir</b> structure appears in the <b>qmail</b> system by Daniel Bernstein. 288 289<b>AUTHOR(S)</b> 290 Wietse Venema 291 IBM T.J. Watson Research 292 P.O. Box 704 293 Yorktown Heights, NY 10598, USA 294 295 Andrew McNamara 296 andrewm@connect.com.au 297 connect.com.au Pty. Ltd. 298 Level 3, 213 Miller St 299 North Sydney 2060, NSW, Australia 300 301 VIRTUAL(8) 302</pre> </body> </html> 303