Manual Pages for UNIX Darwin command on man virtual

VIRTUAL(8) VIRTUAL(8)

NAME

virtual - Postfix virtual domain mail delivery agent

SYNOPSIS

vviirrttuuaall [generic Postfix daemon options]

DESCRIPTION

The vviirrttuuaall(8) delivery agent is designed for virtual mail hosting ser-

vices. Originally based on the Postfix local(8) delivery agent, this agent looks up recipients with map lookups of their full recipient

address, instead of using hard-coded unix password file lookups of the

address local part only. This delivery agent only delivers mail. Other features such as mail

forwarding, out-of-office notifications, etc., must be configured via

virtualalias maps or via similar lookup mechanisms.

MMAAIILLBBOOXX LLOOCCAATTIIOONN

The mailbox location is controlled by the vviirrttuuaallmmaaiillbbooxxbbaassee and vviirr-

ttuuaallmmaaiillbbooxxmmaappss configuration parameters (see below). The vviirr-

ttuuaallmmaaiillbbooxxmmaappss table is indexed by the recipient address as described under TABLE SEARCH ORDER below. The mailbox pathname is constructed as follows:

$$vviirrttuuaallmmaaiillbbooxxbbaassee//$$vviirrttuuaallmmaaiillbbooxxmmaappss((recipient))

where recipient is the full recipient address. UUNNIIXX MMAAIILLBBOOXX FFOORRMMAATT When the mailbox location does not end in //, the message is delivered in UNIX mailbox format. This format stores multiple messages in one textfile. The vviirrttuuaall delivery agent prepends a "FFrroomm sender timestamp" envelope

header to each message, prepends a DDeelliivveerreedd-TToo:: message header with

the envelope recipient address, prepends an XX-OOrriiggiinnaall-TToo:: header with

the recipient address as given to Postfix, prepends a RReettuurrnn-PPaatthh:: mes-

sage header with the envelope sender address, prepends a >> character to lines beginning with "FFrroomm ", and appends an empty line. The mailbox is locked for exclusive access while delivery is in

progress. In case of problems, an attempt is made to truncate the mail-

box to its original length. QQMMAAIILL MMAAIILLDDIIRR FFOORRMMAATT When the mailbox location ends in //, the message is delivered in qmail mmaaiillddiirr format. This format stores one message per file.

The vviirrttuuaall delivery agent daemon prepends a DDeelliivveerreedd-TToo:: message

header with the final envelope recipient address, prepends an XX-OOrriiggii-

nnaall-TToo:: header with the recipient address as given to Postfix, and

prepends a RReettuurrnn-PPaatthh:: message header with the envelope sender

address.

By definition, mmaaiillddiirr format does not require application-level file

locking during mail delivery or retrieval. MMAAIILLBBOOXX OOWWNNEERRSSHHIIPP

Mailbox ownership is controlled by the vviirrttuuaalluuiiddmmaappss and vviirr-

ttuuaallggiiddmmaappss lookup tables, which are indexed with the full recipient address. Each table provides a string with the numerical user and group ID, respectively. The vviirrttuuaallmmiinniimmuummuuiidd parameter imposes a lower bound on numerical user ID values that may be specified in any vviirrttuuaalluuiiddmmaappss. TTAABBLLEE SSEEAARRCCHH OORRDDEERR Normally, a lookup table is specified as a text file that serves as input to the ppoossttmmaapp(1) command. The result, an indexed file in ddbbmm or ddbb format, is used for fast searching by the mail system.

The search order is as follows. The search stops upon the first suc-

cessful lookup. +o When the recipient has an optional address extension the user+extension@domain.tld address is looked up first. With Postfix versions before 2.1, the optional address extension is always ignored. +o The user@domain.tld address, without address extension, is looked up next. +o Finally, the recipient @domain is looked up. When the table is provided via other means such as NIS, LDAP or SQL, the same lookups are done as for ordinary indexed files.

Alternatively, a table can be provided as a regular-expression map

where patterns are given as regular expressions. In that case, only the

full recipient address is given to the regular-expression map.

SSEECCUURRIITTYY

The virtual delivery agent is not security sensitive, provided that the

lookup tables with recipient user/group ID information are adequately protected. This program is not designed to run chrooted. STANDARDS RFC 822 (ARPA Internet Text Messages) DIAGNOSTICS Mail bounces when the recipient has no mailbox or when the recipient is over disk quota. In all other cases, mail for an existing recipient is deferred and a warning is logged. Problems and transactions are logged to ssyyssllooggdd(8). Corrupted message files are marked so that the queue manager can move them to the ccoorrrruupptt queue afterwards.

Depending on the setting of the nnoottiiffyyccllaasssseess parameter, the postmas-

ter is notified of bounces and of other trouble.

BUGS

This delivery agent supports address extensions in email addresses and

in lookup table keys, but does not propagate address extension informa-

tion to the result of table lookup. Postfix should have lookup tables that can return multiple result attributes. In order to avoid the inconvenience of maintaining three tables, use an LDAP or MYSQL database. CCOONNFFIIGGUURRAATTIIOONN PPAARRAAMMEETTEERRSS

Changes to mmaaiinn..ccff are picked up automatically, as virtual(8) processes

run for only a limited amount of time. Use the command "ppoossttffiixx rreellooaadd" to speed up a change. The text below provides only a parameter summary. See postconf(5) for more details including examples. MMAAIILLBBOOXX DDEELLIIVVEERRYY CCOONNTTRROOLLSS vviirrttuuaallmmaaiillbbooxxbbaassee ((eemmppttyy))

A prefix that the virtual(8) delivery agent prepends to all

pathname results from $virtualmailboxmaps table lookups.

vviirrttuuaallmmaaiillbbooxxmmaappss ((eemmppttyy)) Optional lookup tables with all valid addresses in the domains

that match $virtualmailboxdomains.

vviirrttuuaallmmiinniimmuummuuiidd ((110000))

The minimum user ID value that the virtual(8) delivery agent

accepts as a result from $$vviirrttuuaalluuiiddmmaappss table lookup.

vviirrttuuaalluuiiddmmaappss ((eemmppttyy))

Lookup tables with the per-recipient user ID that the virtual(8)

delivery agent uses while writing to the recipient's mailbox. vviirrttuuaallggiiddmmaappss ((eemmppttyy))

Lookup tables with the per-recipient group ID for virtual(8)

mailbox delivery. Available in Postfix version 2.0 and later:

vviirrttuuaallmmaaiillbbooxxddoommaaiinnss (($$vviirrttuuaallmmaaiillbbooxxmmaappss))

The list of domains that are delivered via the $virtualtrans-

port mail delivery transport. vviirrttuuaallttrraannssppoorrtt ((vviirrttuuaall)) The default mail delivery transport for domains that match the

$virtualmailboxdomains parameter value.

LLOOCCKKIINNGG CCOONNTTRROOLLSS

vviirrttuuaallmmaaiillbbooxxlloocckk ((sseeee ''ppoossttccoonnff -dd'' oouuttppuutt))

How to lock a UNIX-style virtual(8) mailbox before attempting

delivery. ddeelliivveerrlloocckkaatttteemmppttss ((2200)) The maximal number of attempts to acquire an exclusive lock on a mailbox file or bounce(8) logfile. ddeelliivveerrlloocckkddeellaayy ((11ss)) The time between attempts to acquire an exclusive lock on a mailbox file or bounce(8) logfile. ssttaalleelloocckkttiimmee ((550000ss)) The time after which a stale exclusive mailbox lockfile is removed. RREESSOOUURRCCEE AANNDD RRAATTEE CCOONNTTRROOLLSS

vviirrttuuaallddeessttiinnaattiioonnccoonnccuurrrreennccyylliimmiitt (($$ddeeffaauullttddeessttiinnaattiioonnccoonnccuurr-

rreennccyylliimmiitt))

The maximal number of parallel deliveries to the same destina-

tion via the virtual message delivery transport.

vviirrttuuaallddeessttiinnaattiioonnrreecciippiieennttlliimmiitt (($$ddeeffaauullttddeessttiinnaattiioonnrreecciippii-

eennttlliimmiitt))

The maximal number of recipients per delivery via the virtual

message delivery transport. vviirrttuuaallmmaaiillbbooxxlliimmiitt ((5511220000000000)) The maximal size in bytes of an individual mailbox or maildir file, or zero (no limit). MMIISSCCEELLLLAANNEEOOUUSS CCOONNTTRROOLLSS

ccoonnffiiggddiirreeccttoorryy ((sseeee ''ppoossttccoonnff -dd'' oouuttppuutt))

The default location of the Postfix main.cf and master.cf con-

figuration files. ddaaeemmoonnttiimmeeoouutt ((1188000000ss)) How much time a Postfix daemon process may take to handle a

request before it is terminated by a built-in watchdog timer.

iippccttiimmeeoouutt ((33660000ss)) The time limit for sending or receiving information over an internal communication channel. mmaaxxiiddllee ((110000ss)) The maximum amount of time that an idle Postfix daemon process waits for the next service request before exiting. mmaaxxuussee ((110000))

The maximal number of connection requests before a Postfix dae-

mon process terminates.

pprroocceessssiidd ((rreeaadd-oonnllyy))

The process ID of a Postfix command or daemon process.

pprroocceessssnnaammee ((rreeaadd-oonnllyy))

The process name of a Postfix command or daemon process.

qquueeuueeddiirreeccttoorryy ((sseeee ''ppoossttccoonnff -dd'' oouuttppuutt))

The location of the Postfix top-level queue directory.

ssyyssllooggffaacciilliittyy ((mmaaiill)) The syslog facility of Postfix logging. ssyyssllooggnnaammee ((ppoossttffiixx)) The mail system name that is prepended to the process name in

syslog records, so that "smtpd" becomes, for example, "post-

fix/smtpd".