/usr/lib/gnats/mail-agent is in gnats-user 4.1.0-3+deb8u1.
This file is owned by root:root, with mode 0o755.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 | #!/bin/sh
# Program to send mail for GNATS.
# Copyright (C) 1999 Free Software Foundation, Inc.
# Contributed by Bob Manson (manson@juniper.net)
#
# This file is part of GNU GNATS.
#
# GNU GNATS is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2, or (at your option)
# any later version.
#
# GNU GNATS is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with GNU GNATS; see the file COPYING. If not, write to
# the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
# This is a rather pointless script, but at least it isolates the number
# of programs that actually invoke the mail agent to 1, making it easy
# to change.
MAIL_AGENT="/usr/sbin/sendmail -oi -t"
exec $MAIL_AGENT $@ > /dev/null
|