nisplus_table(5) Postfix NIS+ client


postmap -q "string" "nisplus:[name=%s];"
postmap -q - "nisplus:[name=%s];" <inputfile


The Postfix mail system uses optional lookup tables. These tables are usually in dbm or db format. Alternatively, lookup tables can be specified as NIS+ databases.

To find out what types of lookup tables your Postfix system supports use the "postconf -m" command.

To test Postfix NIS+ lookup tables, use the "postmap -q" command as described in the SYNOPSIS above.


Most of the NIS+ query is specified via the NIS+ map name. The
general format of a Postfix NIS+ map name is as follows:


Postfix NIS+ map names differ from what one normally would use with commands such as niscat:

  • With each NIS+ table lookup, "%s" is replaced by a version of the lookup string. There can be only one "%s" instance in a Postfix NIS+ map name.
  • Postfix NIS+ map names use ";" instead of ",", because the latter character is special in the Postfix file. Postfix replaces ";" characters in the map name by "," before making NIS+ queries.
  • The ":column" part in the NIS+ map name is not part of the actual NIS+ query. Instead, it specifies the number of the table column that provides the lookup result. When no ":column" is specified the first column (1) is used.


A NIS+ aliases map might be queried as follows:

    alias_maps = dbm:/etc/mail/aliases,

This queries the local aliases file before the NIS+ file.


Use "postconf readme_directory" or
"postconf html_directory" to locate this information.
DATABASE_README, Postfix lookup table overview


The Secure Mailer license must be distributed with this software.


Geoff Gibbs
CB10 1SB, UK
Adopted and adapted by:
Wietse Venema
IBM T.J. Watson Research
P.O. Box 704
Yorktown Heights, NY 10598, USA
Wietse Venema
Google, Inc.
111 8th Avenue
New York, NY 10011, USA