.Dd April 26, 2014
.Dt GREYFIX 8
.Os
.Sh NAME
.Nm greyfix
.Nd "A greylisting policy daemon for Postfix"
.Sh SYNOPSIS
.Nm
.Op Fl Vvd
.Op Fl h Ar home_directory
.Op Fl g Ar delay_period
.Op Fl b Ar bloc_idle_period
.Op Fl p Ar pass_period
.Op Fl r Ar reject_action
.Op Fl G Ar greylist_action
.Op Fl / Ar prefix_size
.Op Fl 6 Ar prefix_size
.Op Fl -dump-triplets
.Op Fl -help
.Sh DESCRIPTION
.Nm
is a efficient greylisting policy daemon for Postfix.
.Pp
The options are:
.Bl -tag -width indent
.It Fl V , Fl -version
Show version information.
.It Fl v , Fl -verbose
Verbose logging.
.It Fl d , Fl -debug
Debug logging.
.It Fl -help
Show usage information.
.It Fl -dump-triplets
Dump the triplets database to stdout. Mostly for debugging purposes.
.It Fl b Ar seconds , Fl -bloc-max-idle Ar seconds
How many seconds of life are given to a record that is created from a new mail
.Em ( ip , from , to )
triplet. Note that the window created by this setting for passing mails is
reduced by the amount set for
.Fl -greylist-delay .
Also see
.Fl -pass-max-idle .
Defaults to 18000.
.It Fl g Ar seconds , Fl -greylist-delay Ar seconds
How many seconds we will block inbound mail that is from a previously unknown
.Em ( ip , from , to )
triplet. If it is set to zero, incoming mail association will be learned, but
no deliveries will be tempfailed. Use a setting of zero with caution, as it
will learn spammers as well as legitimate senders. Defaults to 3480.
.It Fl h Ar home_directory , Fl -home Ar home_directory
Location of the Berkeley DB environment home location. Defaults to
.Pa /var/db/greyfix .
.It Fl p Ar seconds , Fl -pass-max-idle Ar seconds
How long to give to a record we are updating from an allowed (passed) email.
.Pp
The default is 3110400, which should be enough to handle messages that may only
be sent once a month, or on things like the first monday of the month (which
sometimes means 5 weeks). Plus, we add a day for a delivery buffer.
.It Fl r Ar action , Fl -reject-action Ar action
The reject action directive that will be used.  See
.Xr access 5
for valid actions. The placeholder
.Em %d
expand to the number of seconds,
.Em %p
to the empty string if
.Em %d
expands to 1 or
.Dq s
otherwise,
.Em %s
to a single space, and
.Em %%
to
.Dq % .
.Pp
The default is
.Dq DEFER_IF_PERMIT Greylisted by greyfix 0.4.0, try again in %d second%p. See http://www.kim-minh.com/pub/greyfix/ for more information.
.It Fl G Ar action , Fl -greylisted-action Ar action
The action that will be used the first time a triplet passes greylisting. Same
expansion as for
.Fl -reject-action .
.Pp
The default is
.Dq PREPEND X-Greyfix: Greylisted by greyfix 0.4.0 for %d second%p. See http://www.kim-minh.com/pub/greyfix/ for more information.
.It Fl / Ar prefix_size , Fl -network-prefix Ar prefix_size
Only consider the first
.Ar prefix_size
bits of an IPv4 address. Defaults to 32, i.e., the whole address is
significant.
.It Fl 6 Ar prefix_size , Fl -network6-prefix Ar prefix_size
Only consider the first
.Ar prefix_size
bits of an IPv6 address. Defaults to 128, i.e., the whole address is
significant.
.El
.Sh USAGE
Edit Postfix's master configuration file,
.Pa /usr/local/etc/postfix/master.cf ,
and add the following:
.Bd -literal
greyfix    unix  -       n       n       -       -       spawn
  user=nobody argv=/usr/local/sbin/greyfix -/ 24 -6 56
.Ed
.Pp
Edit Postfix's main configuration file,
.Pa /etc/postfix/main.cf ,
and add the following:
.Bd -literal
smtpd_recipient_restrictions =
  permit_mynetworks,
  reject_unauth_destination,
  check_policy_service unix:private/greyfix
.Ed
.Pp
If there is already an
.Em smtpd_recipient_restrictions
configuration line, you should edit it rather than add a new one. The
important part for Greyfix is that you should add
.Em check_policy_service unix:private/greyfix
to it. Finally, have Postfix reload its configuration with
.Ic "postfix reload" .
.Sh NOTES
.Ss Logs
Greyfix logs to
.Xr syslog 3
with the
.Li LOG_MAIL
facility. As such, the log messages should appear along Postfix's.
.Sh ALSO SEE
.Xr access 5
.Sh AUTHORS
.Nm
was written by
.An Kim Minh Kaplan
.Aq http://www.kim-minh.com/ .