.\" Copyright (C) 2020 Ryan Kavanagh <rak@debian.org>
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.Dd April 12, 2020
.Dt FILTER-SENDERSCORE 8
.Os
.Sh NAME
.Nm filter-senderscore
.Nd SenderScore filter for OpenSMTPD
.Sh SYNOPSIS
.Nm filter-senderscore
.Op Fl blockBelow Ar score
.Op Fl blockPhase Ar phase
.Op Fl junkBelow  Ar score
.Op Fl slowFactor Ar factor
.Op Fl scoreHeader
.Sh DESCRIPTION
The
.Nm
filter for the OpenSMTPD
.Pq Xr smtpd 8
server filters sessions based on their SenderScores reputation score.
Its options are:
.Bl -tag -width scoreHeader
.It Fl blockBelow Ar score
Displays an error banner for sessions with a reputation score below
.Ar score
and then disconnects.
.It Fl blockPhase Ar phase
Determines at which phase
.Fl blockBelow
is triggered.
The default is
.Ar connect .
Valid choices are
.Ar connect ,
.Ar helo ,
.Ar ehlo ,
.Ar starttls ,
.Ar auth ,
.Ar mail-from ,
.Ar rcpt-to ,
and
.Ar quit .
Note that
.Ar quit
will result in a message at the end of a session and may only be used to warn
the sender that its reputation is degrading, as it will not prevent transactions
from succeeding.
.It Fl junkBelow Ar score
Prepends a
.Ql X-Spam: yes
header to messages for sessions with a reputation score below
.Ar score .
.It Fl slowFactor Ar factor
Delays all answers by this many milliseconds, where
.Ql score
is the reputation score:
.Dl factor \(mi ((factor \(di 100) \(** score)
.It Fl scoreHeader
Adds an
.Ql X-SenderScore
header with the sender's reputation score if known.
.El
.Sh EXIT STATUS
.Ex -std
.Sh EXAMPLES
Adding the following to
.Pa smtpd.conf
enables
.Nm
for all incoming connections.
.Bd -literal
filter "senderscore" proc-exec \\
       "/usr/local/bin/filter-senderscore -blockBelow 50 \\
                                          -junkBelow  80 \\
                                          -slowFactor 1000"

listen on all filter "senderscore"
.Ed
.Sh SEE ALSO
.Xr smtpd.conf 5
.Sh AUTHORS
.Nm
is Copyright \(co 2019
.An -nosplit
.An Gilles Chehade Aq Mt gilles@poolp.org .
This man page is Copyright \(co 2020
.An Ryan Kavanagh Aq Mt rak@debian.org .
Both are distributed under the ISC license.
.Sh BUGS
None known.