NAME

generic - Postfix generic table format

SYNOPSIS


ppoossttmmaapp //eettcc//ppoossttffiixx//ggeenneerriicc

ppoossttmmaapp --qq ""_s_t_r_i_n_g"" //eettcc//ppoossttffiixx//ggeenneerriicc

ppoossttmmaapp --qq -- //eettcc//ppoossttffiixx//ggeenneerriicc <<_i_n_p_u_t_f_i_l_e

DESCRIPTION

The optional ggeenneerriicc(5) table specifies an address mapping that applies when mail is delivered. This is the opposite of ccaannoonniiccaall(5) mapping, which applies when mail is received.

Typically, one would use the ggeenneerriicc(5) table on a system that does not have a valid Internet domain name and that uses something like _l_o_c_a_l_d_o_m_a_i_n_._l_o_c_a_l instead. The ggeenneerriicc(5) table is then used by the ssmmttpp(8) client to transform local mail addresses into valid Internet mail addresses when mail has to be sent across the Internet. See the EXAMPLE section at the end of this document.

The ggeenneerriicc(5) mapping affects both message header addresses (i.e. addresses that appear inside messages) and message envelope addresses (for example, the addresses that are used in SMTP protocol commands).

Normally, the ggeenneerriicc(5) 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. Execute the command "ppoossttmmaapp //eettcc//ppoossttffiixx//ggeenneerriicc" to rebuild an indexed file after changing the corresponding text file.

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, the table can be provided as a regular-expression map where patterns are given as regular expressions, or lookups can be directed to TCP-based server. In those case, the lookups are done in a slightly different way as described below under "REGULAR EXPRESSION TABLES" or "TCP-BASED TABLES".

CASE FOLDING



The search string is folded to lowercase before database
lookup. As of Postfix 2.3, the search string is not case
folded with database types such as regexp: or pcre: whose
lookup fields can match both upper and lower case.

TABLE FORMAT



The input format for the ppoossttmmaapp(1) command is as follows:
_p_a_t_t_e_r_n _r_e_s_u_l_t When _p_a_t_t_e_r_n matches a mail address, replace it by the
corresponding _r_e_s_u_l_t.
blank lines and comments Empty lines and whitespace-only lines are ignored, as
are lines whose first non-whitespace character is a `#'.
multi-line text A logical line starts with non-whitespace text. A line that
starts with whitespace continues a logical line.


With lookups from indexed files such as DB or DBM, or from networked
tables such as NIS, LDAP or SQL, patterns are tried in the order as
listed below:
_u_s_e_r@_d_o_m_a_i_n _a_d_d_r_e_s_s Replace _u_s_e_r@_d_o_m_a_i_n by _a_d_d_r_e_s_s. This form
has the highest precedence.
_u_s_e_r _a_d_d_r_e_s_s Replace _u_s_e_r@_s_i_t_e by _a_d_d_r_e_s_s when _s_i_t_e is
equal to $mmyyoorriiggiinn, when _s_i_t_e is listed in $mmyyddeessttiinnaattiioonn, or when it is listed in $iinneett__iinntteerrffaacceess or $pprrooxxyy__iinntteerrffaacceess.
@_d_o_m_a_i_n _a_d_d_r_e_s_s Replace other addresses in _d_o_m_a_i_n by _a_d_d_r_e_s_s.
This form has the lowest precedence.

RESULT ADDRESS REWRITING



The lookup result is subject to address rewriting:
· When the result has the form @_o_t_h_e_r_d_o_m_a_i_n, the
result becomes the same _u_s_e_r in _o_t_h_e_r_d_o_m_a_i_n.
· When "aappppeenndd__aatt__mmyyoorriiggiinn==yyeess", append "@@$$mmyyoorriiggiinn"
to addresses without "@domain".
· When "aappppeenndd__ddoott__mmyyddoommaaiinn==yyeess", append
"..$$mmyyddoommaaiinn" to addresses without ".domain".

ADDRESS EXTENSION



When a mail address localpart contains the optional recipient delimiter
(e.g., _u_s_e_r_+_f_o_o@_d_o_m_a_i_n), the lookup order becomes:
_u_s_e_r_+_f_o_o@_d_o_m_a_i_n, _u_s_e_r@_d_o_m_a_i_n, _u_s_e_r_+_f_o_o,
_u_s_e_r, and @_d_o_m_a_i_n.
        

The pprrooppaaggaattee__uunnmmaattcchheedd__eexxtteennssiioonnss parameter controls whether an unmatched address extension (_+_f_o_o) is propagated to the result of table lookup.

REGULAR EXPRESSION TABLES



This section describes how the table lookups change when the table
is given in the form of regular expressions. For a description of
regular expression lookup table syntax, see rreeggeexxpp__ttaabbllee(5)
or ppccrree__ttaabbllee(5).
        

Each pattern is a regular expression that is applied to the entire address being looked up. Thus, _u_s_e_r_@_d_o_m_a_i_n mail addresses are not broken up into their _u_s_e_r and _@_d_o_m_a_i_n constituent parts, nor is _u_s_e_r_+_f_o_o broken up into _u_s_e_r and _f_o_o.

Patterns are applied in the order as specified in the table, until a pattern is found that matches the search string.

Results are the same as with indexed file lookups, with the additional feature that parenthesized substrings from the pattern can be interpolated as $$11, $$22 and so on.

TCP-BASED TABLES



This section describes how the table lookups change when lookups
are directed to a TCP-based server. For a description of the TCP
client/server lookup protocol, see ttccpp__ttaabbllee(5).
This feature is not available up to and including Postfix version 2.4.
        

Each lookup operation uses the entire address once. Thus, _u_s_e_r_@_d_o_m_a_i_n mail addresses are not broken up into their _u_s_e_r and _@_d_o_m_a_i_n constituent parts, nor is _u_s_e_r_+_f_o_o broken up into _u_s_e_r and _f_o_o.

Results are the same as with indexed file lookups.

EXAMPLE



The following shows a generic mapping with an indexed file.
When mail is sent to a remote host via SMTP, this replaces
_h_i_s_@_l_o_c_a_l_d_o_m_a_i_n_._l_o_c_a_l by his ISP mail address, replaces
_h_e_r_@_l_o_c_a_l_d_o_m_a_i_n_._l_o_c_a_l by her ISP mail address, and
replaces other local addresses by his ISP account, with
an address extension of _+_l_o_c_a_l (this example assumes
that the ISP supports "+" style address extensions).
        


/etc/postfix/main.cf:
    smtp_generic_maps = hash:/etc/postfix/generic

/etc/postfix/generic: his@localdomain.local hisaccount@hisisp.example her@localdomain.local heraccount@herisp.example @localdomain.local hisaccount+local@hisisp.example

Execute the command "ppoossttmmaapp //eettcc//ppoossttffiixx//ggeenneerriicc" whenever the table is changed. Instead of hhaasshh, some systems use ddbbmm database files. To find out what tables your system supports use the command "ppoossttccoonnff --mm".

BUGS

The table format does not understand quoting conventions.

CONFIGURATION PARAMETERS



The following mmaaiinn..ccff parameters are especially relevant.
The text below provides only a parameter summary. See
ppoossttccoonnff(5) for more details including examples.
ssmmttpp__ggeenneerriicc__mmaappss Address mapping lookup table for envelope and header sender
and recipient addresses while delivering mail via SMTP.
pprrooppaaggaattee__uunnmmaattcchheedd__eexxtteennssiioonnss A list of address rewriting or forwarding mechanisms that propagate
an address extension from the original address to the result. Specify zero or more of ccaannoonniiccaall, vviirrttuuaall, aalliiaass, ffoorrwwaarrdd, iinncclluuddee, or ggeenneerriicc.

Other parameters of interest:

iinneett__iinntteerrffaacceess The network interface addresses that this system receives mail on.
You need to stop and start Postfix when this parameter changes.
pprrooxxyy__iinntteerrffaacceess Other interfaces that this machine receives mail on by way of a
proxy agent or network address translator.
mmyyddeessttiinnaattiioonn List of domains that this mail system considers local.
mmyyoorriiggiinn The domain that is appended to locally-posted mail.
oowwnneerr__rreeqquueesstt__ssppeecciiaall Give special treatment to oowwnneerr--_x_x_x and _x_x_x--rreeqquueesstt
addresses.

SEE ALSO


postmap(1), Postfix lookup table manager
postconf(5), configuration parameters
smtp(8), Postfix SMTP client

README FILES



Use "ppoossttccoonnff rreeaaddmmee__ddiirreeccttoorryy" or
"ppoossttccoonnff hhttmmll__ddiirreeccttoorryy" to locate this information.

ADDRESS_REWRITING_README, address rewriting guide
DATABASE_README, Postfix lookup table overview
STANDARD_CONFIGURATION_README, configuration examples

LICENSE



The Secure Mailer license must be distributed with this software.

HISTORY


A genericstable feature appears in the Sendmail MTA.

This feature is available in Postfix 2.2 and later.

AUTHOR(S)


Wietse Venema
IBM T.J. Watson Research
P.O. Box 704
Yorktown Heights, NY 10598, USA