aliases - addresses and aliases for sendmail
/etc/mail/aliases /etc/mail/aliases.db /etc/mail/aliases.dir /etc/mail/aliases.pag ~/.forward
aliases(5) File Formats aliases(5)
NAME
aliases, addresses, forward - addresses and aliases for sendmail
SYNOPSIS
/etc/mail/aliases
/etc/mail/aliases.db
/etc/mail/aliases.dir
/etc/mail/aliases.pag
~/.forward
DESCRIPTION
These files contain mail addresses or aliases, recognized by send-
mail(8) for the local host:
/etc/passwd
Mail addresses (usernames) of local users.
/etc/mail/aliases
Aliases for the local host, in ASCII format. Root can edit this
file to add, update, or delete local mail aliases.
/etc/mail/aliases.{dir , pag}
The aliasing information from /etc/mail/aliases, in binary ndbm(3C)
format for use by sendmail(8). The program newaliases(8) maintains
these files.
/etc/mail/aliases.db
The aliasing information from /etc/mail/aliases, in binary, Berke-
ley DataBase format for use by sendmail(8). The program maintains
these files.
Depending on the configuration of the AliasFile option in
/etc/mail/sendmail.cf, either the single file aliases.db or the
pair of files aliases.{dir, pag} is generated by newaliases(8). As
shipped with Solaris, sendmail(8) supports both formats. If neither
is specified, the Berkeley DataBase format which generates the sin-
gle .db file is used.
~/.forward
Addresses to which a user's mail is forwarded (see Automatic For-
warding).
In addition, the NIS name services aliases map mail.aliases contains
addresses and aliases available for use across the network.
Addresses
As distributed, sendmail(8) supports the following types of addresses:
Local Usernames
username
Each local username is listed in the local host's /etc/passwd file.
Local Filenames
pathname
Messages addressed to the absolute pathname of a file are appended to
that file.
Commands
|command
If the first character of the address is a vertical bar (|), send-
mail(8) pipes the message to the standard input of the command the bar
precedes.
Internet-standard Addresses
username@domain
If domain does not contain any `.' (dots), then it is interpreted as
the name of a host in the current domain. Otherwise, the message is
passed to a mailhost that determines how to get to the specified
domain. Domains are divided into subdomains separated by dots, with the
top-level domain on the right.
For example, the full address of John Smith could be:
js@jsmachine.Podunk-U.EDU
if he uses the machine named jsmachine at Podunk University.
uucp Addresses
... [host!] host!username
These are sometimes mistakenly referred to as ``Usenet'' addresses.
uucp(1C) provides links to numerous sites throughout the world for the
remote copying of files.
Other site-specific forms of addressing can be added by customizing the
sendmail.cf configuration file. See sendmail(8) for details. Standard
addresses are recommended.
Aliases
Local Aliases
/etc/mail/aliases is formatted as a series of lines of the form
aliasname:address[, address]
aliasname is the name of the alias or alias group, and address is the
address of a recipient in the group. Aliases can be nested. That is, an
address can be the name of another alias group. Because of the way
sendmail(8) performs mapping from upper-case to lower-case, an address
that is the name of another alias group must not contain any upper-case
letters.
Lines beginning with white space are treated as continuation lines for
the preceding alias. Lines beginning with # are comments.
Special Aliases
An alias of the form:
owner-aliasname : address
sendmail directs error-messages resulting from mail to aliasname to
address, instead of back to the person who sent the message. sendmail
rewrites the SMTP envelope sender to match this, so owner-aliasname
should always point to alias-request, and alias-request should point to
the owner's actual address:
owner-aliasname: aliasname-request
aliasname-request address
An alias of the form:
aliasname: :include:pathname
with colons as shown, adds the recipients listed in the file pathname
to the aliasname alias. This allows a private list to be maintained
separately from the aliases file.
NIS Domain Aliases
The aliases file on the master NIS server is used for the mail.aliases
NIS map, which can be made available to every NIS client. Thus, the
/etc/mail/aliases* files on the various hosts in a network will one day
be obsolete. Domain-wide aliases should ultimately be resolved into
usernames on specific hosts. For example, if the following were in the
domain-wide alias file:
jsmith:js@jsmachine
then any NIS client could just mail to jsmith and not have to remember
the machine and username for John Smith.
If an NIS alias does not resolve to an address with a specific host,
then the name of the NIS domain is used. There should be an alias of
the domain name for a host in this case.
For example, the alias:
jsmith:root
sends mail on an NIS client to root@podunk-u if the name of the NIS
domain is podunk-u.
Automatic Forwarding
When an alias (or address) is resolved to the name of a user on the
local host, sendmail(8) checks for a ~/.forward file, owned by the
intended recipient, in that user's home directory, and with universal
read access. This file can contain one or more addresses or aliases as
described above, each of which is sent a copy of the user's mail.
Care must be taken to avoid creating addressing loops in the ~/.forward
file. When forwarding mail between machines, be sure that the destina-
tion machine does not return the mail to the sender through the opera-
tion of any NIS aliases. Otherwise, copies of the message may bounce.
Usually, the solution is to change the NIS alias to direct mail to the
proper destination.
A backslash before a username inhibits further aliasing. For instance,
to invoke the vacation program, user js creates a ~/.forward file that
contains the line:
\js, "|/usr/bin/vacation js"
so that one copy of the message is sent to the user, and another is
piped into the vacation program.
The ~/.forward file can be used to specify special "per user" exten-
sions by creating a .forward+extension file in the home directory. For
example, with an address like jsmith+jerry@jsmachine, the sendmail(8)
utility recognizes everything before the "+" as the actual username
(jsmith) and everything after it, up to the "@" symbol, as the exten-
sion (jerry) which is passed to the mail delivery agent for local use.
The default value of the ForwardPath processing option in sendmail(8)
is:
O ForwardPath=$z/.forward.$w+$h:$z/.forward+$h:$z/.forward.$w:$z \
/.forward
where $z is the macro for the user's home directory, $w is the macro
for the local machine name and $h is the extension. For example, for
mail using the address, jsmith+jerry@jsmachine, the sendmail(8) utility
checks each of the four following file names, in the order given, to
see if it exists and if it has "safe" permissions, that is, that nei-
ther the file nor any of its parent directories are group- or world-
writable:
~jsmith/.forward.jsmachine+jerry
~jsmith/.forward+jerry
~jsmith/.forward.jsmachine
~jsmith/.forward
The first file that meets the conditions is used to forward the mail,
that is, all the entries in that file receive a copy of the mail. The
search is then stopped.
FILES
/etc/passwd Password file
/etc/nsswitch.conf Name service switch configuration file
/etc/mail/aliases Mail aliases file (ascii)
/etc/mail/aliases.db Database of mail aliases (binary)
/etc/mail/aliases.dir Database of mail aliases (binary)
/etc/mail/aliases.pag Database of mail aliases (binary)
/etc/mail/sendmail.cf sendmail configuration file
~/.forward Forwarding information file
ATTRIBUTES
See attributes(7) for descriptions of the following attributes:
+-----------------------------+------------------------------+
| ATTRIBUTE TYPE | ATTRIBUTE VALUE |
+-----------------------------+------------------------------+
|Availability |service/network/smtp/sendmail |
+-----------------------------+------------------------------+
SEE ALSO
passwd(1), uucp(1C), vacation(1), ndbm(3C), getusershell(3C),
passwd(5), shells(5), attributes(7), newaliases(8), sendmail(8)
NOTES
Because of restrictions in ndbm(3C), a single alias cannot contain more
than about 1000 characters (if this format is used). The Berkeley Data-
Base format does not have any such restriction. Nested aliases can be
used to circumvent this limit.
For aliases which result in piping to a program or concatenating a
file, the shell of the controlling user must be allowed. Which shells
are and are not allowed are determined by getusershell(3C).
Solaris 11.4 8 Mar 2016 aliases(5)