NAME
table —
format description for smtpd
tables
DESCRIPTION
This manual page documents the file format for the various tables used in the smtpd(8) mail daemon.
The format described here applies to tables as defined in smtpd.conf(5).
TABLE TYPES
There are two types of tables: lists and mappings. A list consists of a series of values, while a mapping consists of a series of keys and their associated values. The following illustrates how to declare them as static tables:
table mylist { value1, value2, value3 }
table mymapping { key1 = value1, key2 = value2, key3 = value3 }
When using a ‘file’ table, a
list will be written with each value on a line by itself.
value1 value2 value3
A mapping will be written with each key and value on a line, whitespace and an optional colon separating both columns:
key1: value1 key2 value2 key3 value3
Blank lines, leading and trailing spaces and tabs are ignored. Lines whose first non-space character is a hash mark (‘#’) are comments and are ignored. To force the parsing of a file table as a list rather than a mapping, use this special comment:
# @listA file table can be converted to a Berkeley database using the makemap(8) utility with no syntax change.
Tables using a ‘file’ or
Berkeley DB backend will be referenced as follows:
tablenamefile:/path/to/filetablenamedb:/path/to/file.db
Aliasing tables
Aliasing tables are mappings that associate a recipient to one or many destinations. They can be used in two contexts: primary domain aliases and virtual domain mapping.
actionname methodalias<table>actionname methodvirtual<table>
In a primary domain context, the key is the user part of the recipient address, whilst the value is one or many recipients as described in aliases(5):
user1 otheruser user2 otheruser1,otheruser2 user3 [email protected]
In a virtual domain context, the key is either a user part, a full email address or a catch-all, following selection rules described in smtpd.conf(5), and the value is one or many recipients as described in aliases(5):
user1 otheruser [email protected] otheruser1,otheruser2 @example.org [email protected] @ [email protected]
The following directive shares the same table format, but with a different meaning. Here, the user is allowed to send mail from the listed addresses:
listen oninterfaceauth[...]senders<table>
Domain tables
Domain tables are simple lists of domains or hosts.
matchfor domain<table>actionnamematchhelo<table> [...]actionname
In that context, the list of domains will be matched against the
recipient domain or against the HELO name advertised by the sending host,
respectively. For ‘static’,
‘file’ and
dbopen(3)
backends, a wildcard may be used so the domain table may contain:
example.org *.example.org
Credentials tables
Credentials tables are mappings of credentials. They can be used in two contexts:
listen oninterfacetls[...]auth<table>actionnamerelay hostrelay-urlauth<table>
In a listener context, the credentials are a mapping of username and encrypted passwords:
user1 $2b$10$hIJ4QfMcp.90nJwKqGbKM.MybArjHOTpEtoTV.DgLYAiThuoYmTSe user2 $2b$10$bwSmUOBGcZGamIfRuXGTvuTo3VLbPG9k5yeKNMBtULBhksV5KdGsK
The passwords are to be encrypted using the smtpctl(8) encrypt subcommand.
In a relay context, the credentials are a mapping of labels and username:password pairs:
label1 user:password
The label must be unique and is used as a selector for the proper credentials when multiple credentials are valid for a single destination. The password is not encrypted as it must be provided to the remote host.
Netaddr tables
Netaddr tables are lists of IPv4 and IPv6 network addresses. They can only be used in the following context:
match from
src <table> action
nameWhen used as a "from source", the address of a client is compared to the list of addresses in the table until a match is found.
A netaddr table can contain exact addresses or netmasks, and looks as follow:
192.168.1.1 [::1] 192.168.1.0/24
IPv6 addresses must be enclosed in square brackets.
Userinfo tables
Userinfo tables are used in rule context to specify an alternate userbase, mapping virtual users to local system users by UID, GID and home directory.
action name
method userbase
<table>A userinfo table looks as follows:
joe 1000:100:/home/virtual/joe jack 1000:100:/home/virtual/jack
In this example, both joe and jack are virtual users mapped to the local system user with UID 1000 and GID 100, but different home directories. These directories may contain a forward(5) file. This can be used in conjunction with an alias table that maps an email address or the domain part to the desired virtual username. For example:
[email protected] joe [email protected] jack
Source tables
Source tables are lists of IPv4 and IPv6 addresses. They can only be used in the following context:
action
name relay src
<table>Successive queries to the source table will return the elements one by one.
A source table looks as follow:
192.168.1.2 192.168.1.3 [::1] [::2]
IPv6 address must be enclosed in square brackets.
Mailaddr tables
Mailaddr tables are lists of email addresses. They can be used in the following contexts:
matchmail-from<table>actionnamematchrcpt-to<table>actionname
A mailaddr entry is used to match an email address against a username, a domain or a full email address. A "*" wildcard may be used in part of the domain name.
A mailaddr table looks as follow:
user @domain user@domain user@*.domain
Addrname tables
Addrname tables are used to map IP addresses to hostnames. They can be used in both listen context and relay context:
listen oninterfacehostnames<table>actionnamerelay helo-src<table>
In listen context, the table is used to look up the server name to advertise depending on the local address of the socket on which a connection is accepted. In relay context, the table is used to determine the hostname for the HELO sequence of the SMTP protocol, depending on the local address used for the outgoing connection.
The format is a mapping from inet4 or inet6 addresses to hostnames:
[::1] localhost 127.0.0.1 localhost 88.190.23.165 www.opensmtpd.org
IPv6 addresses must be enclosed in square brackets.