makealiases — Create an alias database
makealiases [-protocol=protocol] [-alias=filename] [-src=pathname] [-tmp=filename] [-chk] [-dump] [module]
The Courier mail server's
/etc/courier/aliases.dat file is a unified
implementation of sendmail-style address aliasing, qmail-style virtual
domains, plus several
Courier mail server-style
enhancements.
The term aliasing refers to substituting one or more addresses for another address. A one-to-one substitution results in the Courier mail server accepting mail for one address, and delivering the mail to another address. A one-to-many substitution results in the Courier mail server accepting mail for one address, and delivering a separate copy of the message to every address defined by the alias.
/etc/courier/aliases.dat is a binary database file.
makealiases creates the binary database file by reading the
aliases from plain text files, and makealiases creates
/etc/courier/aliases.dat by default.
makealiases creates /etc/courier/aliases.dat from
one or more source files, which are plain text files that may be created by
any text editor. The format of those source files is defined below. By
default, makealiases obtains the source text from
/etc/courier/aliases. If this is a text file, it is used
verbatim. If this is a directory (the
Courier mail server creates it as
a directory by
default), all the non-hidden files in this directory are concatenated
together.
filename
Create filename, instead of
/etc/courier/aliases.dat.
Try to search for bad addresses used in the
aliases.dat file. This option takes some time to
complete. It
does not create an aliases.dat file, but instead tries to
check every address specified by the source text file. Why is this
necessary? That's because non-delivery reports will not be sent to the
sender for failures in delivering mail to an aliased address. This is by
design. the Courier mail server
considers aliases to be private mailing lists. Because
non-delivery notices are not sent, bad addresses will not be immediately
detected.
The -chk option is really effective for
addresses which are local, because there is no real way to determine if a
remote mail address is valid.
Do not create aliases.dat, instead
display the contents of the alias database, in plain text form. The
contents will be the combined contents of all the source files, with all
addresses converted to canonical format, with duplicates removed and
sub-aliases expanded.
pathname
Use pathname instead of
/etc/courier/aliases as the source file.
pathname can
also refer to a directory. This concatenates every non-hidden file in the
directory.
filename
Use filename as a temporary
file, instead of /etc/courier/aliases.tmp.
makealiases requires a temporary file for its own purposes,
which is automatically removed when done. This temporary file MUST reside
on the same filesystem as aliases.dat. If the
-alias option specifies a file on a different filesystem, use
this option to specify where to temporary place a file in the same
filesystem. Because makealiases always uses the same name
for
a temporary file you cannot run more than one makealiases
process at the same time.
protocol
Use an alias list that's
private to messages coming from protocol. See below.
The optional module specifies the module
whose rewriting rules are used
to convert E-mail addresses into a canonical form. If not specified, the
local module's address rewriting rules will be used.
Addresses in /etc/courier/aliases.dat will be checked in every
message. Use the -protocol option to create aliases that will be
checked only for message that are received via a specific protocol, such as
ESMTP, UUCP, or locally-generated mail. This allows you, for example, to
create an alias such as "everyone", which is only avaliable to locally
generated mail, and does not work for mail received via ESMTP. The argument to
the -protocol option is one of: esmtp,
uucp, or local.
Protocol-specific alias files are
/etc/courier/aliases-, where "protocol.datprotocol"
is the specific protocol, such as "local", "esmtp", or "uucp", and the source
file read by makealiases would be
/etc/courier/aliases-. If the
protocol-protocol option is specified, makealiases will
access these files instead of /etc/courier/aliases.dat and
/etc/courier/aliases.
The sources file used to create the binary aliases.dat
database are plain text files that may be created using any editor.
Each alias specification takes the following form:
alias: address1, address2, ...
Mail received by the Courier mail
server addressed to alias will be delivered to the
list of addresses specified. The list of addresses may be split across
multiple lines, if the second and subsequent line starts with a space
character.
Lines starting with the # character are ignored, they are comments.
alias is not restricted to be a local address.
It may be any valid
RFC 2822
address. All addresses do not necessary have to be in a canonical
form.
alias: :include:/absolute/pathname
This notation reads the list of addresses from another file,
/absolute/pathname.
This file should contain one address per line
(comma separated addresses on the same line will also work).
If alias refers to a local, existing,
account, this
account will never get any mail. Any mail with the account listed as recipient
will be redirected to all the addresses specified for that alias. To have a
copy of the mail delivered to the account, define it as one of the addresses
in the alias itself. For example:
larry: larry, moe, curly, shemp
Larry will still receive his mail, but copies will will also be sent to Moe, Curly, and Shemp. If Larry wasn't specified in the alias, he would never get any mail, it will all be forwarded to Moe, Curly, and Shemp.
Alias definitions may refer to other alias definitions, and makealiases automatically incorporates addresses from other aliases. If the same address is listed in multiple aliases, and two or more of them are specified as recipients of the same message, only one copy of the message will be delivered to the address.
The following special syntax implements a virtual domain. A virtual domain redirects all mail for an entire domain to one user:
@domain: user
This special entry results in any recipient address of the form
foo@domain to be rewritten as
user-foo@me, where
me is the hostname of the machine,
which we expect to be a local domain.
The following examples use the alias entry "@example.com:
john", and "domain.com" is in the
control/me
file. The address "postmaster@example.com" becomes
"john-postmaster@domain.com", and
"sales-info@example.com" becomes
"john-sales-info@domain.com".
The intended behavior is to use an actual account named
john.
As a result of the virtual domain address rewriting, delivery instructions for
postmaster@example.com can now be specified by
john's $HOME/.courier-postmaster file,
and delivery
instructions for sales-info@example.com may be specified by
$HOME/.courier-sales-info. john's
$HOME/.courier-default may be used to specify delivery
instructions for any other address in the example.com
domain,
which does not have an explicit .courier file.
If the alias entry was "@example.com: john-example", the
corresponding files in john's $HOME
directory are
.courier-example-postmaster,
.courier-example-sales-info, and
.courier-example-default. See
dot-courier(5)
for more information on .courier files.
Virtual domain rewriting is NOT recursive, unlike regular aliases. For example:
tom: john@example.com @example.com: larry
You should explicitly expand the alias out:
tom: larry-john
The following notation associates an address directly with a mailbox, or with a program:
info: /var/shared/info
Messages addressed to "info" will be delivered to the mailbox or maildir
/var/shared/info. A full pathname must be
specified.
info: | /usr/local/shared/info
Mail addressed to "info" will be delivered to the indicated program. The program receives each message on standard input.
Program/mailbox delivery notation is primarily used to support legacy
sendmail aliases entries. This is considered to be a legacy feature, and new
installations should create a
dot-courier(5)
file with the
necessary delivery instructions. In fact, aliases for programs or mailboxes
is not directly supported by the Courier
mail server's aliasing mechanisms. It's implemented
by having the makealiases script automatically create a
.courier file, and point the alias address to it.
See dot-courier(5) for more information.
Unlike sendmail, the Courier mail server
delivers as user "daemon"
(group daemon) when delivering to programs or mailboxes.
The following notation allows mail addressed to a certain domain to be forwarded via uucp:
@domain: uucp!bang!path!
The trailing ! tells the
Courier mail server not to append a dash,
so user@domain gets rewritten as
uucp!bang!path!user,
and not uucp!bang!path-user, which is probably not what you
want.
An alias with only one address does not affect delivery status notification attributes of an E-mail message.
An alias with multiple addresses is treated like a private mailing list, as defined by RFC 1894. If the message requests a successful delivery notification, the Courier mail server generates a delivery status notification for the successful delivery to the aliased address, and each alias recipient address will have DSNs set to NEVER.
This has nothing to do with the Courier mail server's support for a Qmail-style alias account.
owner-foo feature of sendmail's aliasing is not
supported.
the Courier mail server normally tries to eliminate duplicate addresses listed as recipients for the same message. Some mail servers are not capable of delivering messages with multiple recipients, and will transmit a separate copy of the same message addressed to each recipient. The Courier mail server can't do anything in this case. Each copy of the same original text is considered an individual, separate, message.
Duplicate elimination can fail in certain rare circumstances, involving exotic features of RFC 2822 concerning case sensitivity.
"@example.com: jack, jill" is allowed, but strongly
discouraged under the penalty of law.
Because multiple-recipient aliases are treated like private mailing lists, failure DSNs are turned off, and a bad recipient address is hardly noticed by anyone.
The makealiases command may execute while the Courier mail server is running, and any changes take effect immediately. However, only one instance of makealiases is permitted to run at the same time.