.TH SMTPFWDD 8 "August 2007" "OpenFWTK"
.SH NAME
smtpfwdd \- SMTP proxy (server portion)
.SH SYNOPSIS
.B smtpfwdd 
.SH DESCRIPTION
.IX  "smtpfwdd"  ""  "\(em SMTP proxy (server portion)"
The Firewall Toolkit
.B smtpfwdd
proxy is an application level proxy that provides configurable
access control and logging  mechanisms. The
.B smtpd
client proxy together with the
.B smtpfwdd
server proxy, which run on the firewall, transfer mail between
internal and external mail servers, using rules you supply.
.PP
All packets, and therefore all application requests go to the
firewall.  On the firewall, the
.B smtpd
and
.B smtpfwdd
proxy software relay information from one side of the firewall to
the other.  They prevent versions of
.I sendmail
on the external network from talking with versions of
.I sendmail
on the internal network, and vice versa. No IP packets pass from
one side of the firewall to the other.  All data is passed at the
application level.
. PP
The server portion of the SMTP proxy
.RB "(" smtpfwdd ")"
generally runs as a daemon (invoked from
.IR "/etc/rc.local" ).
Periodically, based on a configurable value (by default every 60
seconds), the server daemon
.RB "(" smtpfwdd ")"
wakes up and checks to see if there is any new mail that the SMTP
client proxy
.RB "(" smtpd ")"
has placed in the spool directory.  The
.B smtpfwdd
daemon checks the headers of the mail for formatting problems.  It
then calls the configured message transfer agent (usually
.B ssmtp 
sendmail emulator) for final delivery
.SH OPTIONS
.SS Command Line Options
None.
.SS Configuration Options
The
.B smtpfwdd
proxy reads configuration rules from the
.IR "/usr/local/etc/netperm-table" .
It reads all rules using the
.B smtpfwdd
,
.B smapd
and
.B *
(wildcard) keywords. The
.B smtpfwdd
proxy reads the
.I netperm-table
from top to bottom.  If there are multiple rules in the table that
could apply for a particular attribute, the
.B smtpfwdd
proxy uses the first one that it finds.  See
.BR "netperm-table"  (5)
for a more complete explanation of 
.I netperm-table
syntax and precedence.
.B smapd
configuration options are included for TIS fwtk compatibility.
.PP
The
.B smtpfwdd
proxy recognizes the following attributes:
.TP
.TP
.BI "badadmin " user
Specifies the username to which the
.B smtpfwdd
server forwards mail that it cannot deliver.
.RS
.TP
.I user
Specifies a user name or alias.
.RE
.TP
.BI "baddir " directory
Specifies the directory in which the
.B smtpfwdd
server places any spooled mail that it cannot deliver normally.
.RS
.TP
.I directory
Specifies a directory on the same device as the spool directory.
Do not include a trailing slash (/) character.  Ensure that this
directory has the same owner and permission as the normal directory
that
.B smtpd
uses.
.RE
.TP
.BI "directory " directory
Specifies the directory that the
.B smtpfwdd
proxy makes its root directory before providing service.
.TP
.BI "groupid " group
Specifies the name of the group the
.B smtpfwdd
proxy uses when running.
.RS
.TP
.I group
Specifies either a name or numeric id from the
.I /etc/group
file.
.RE
.TP
.BI "maxchildren " children
Specifies the maximum number of child processes the
.B smtpfwdd
server can fork to handle mail.
.TP
.BI pidfile file
Specifies a file name where daemon stores master process PID.
.TP
.BI "sendmail " program
Specifies an alternate path for
.BR ssmtp ,
or another mail delivery program you are using to deliver your mail
inside your perimeter.
.TP
.BI "userid " user
Specifies the user ID the proxy uses when running.
.RS
.TP
.I user
Specifies either a name or numeric id from the
.I /etc/passwd
file.
.RE
.TP
.BI "wakeup " seconds
Specifies the number of seconds that the
.B smtpfwdd
server sleeps between scans of the spool directory.  If no value
is specified,
.B smtpfwdd
uses a default value of 60 seconds.
.SH EXAMPLES
This example places the undelivered mail in the
.I /var/spool/smtpd/badmail
directory:
.sp 1
.nf
.na
.RS
smtpfwdd:  baddir /var/spool/smtpd/badmail
.RE
.fa
.fi
.SH FILES
.IP /etc/rc.local
Command script that controls automatic reboot, and includes startup
information for the
.B smtpfwdd
proxy.
.IP /usr/local/etc/netperm-table
The network permissions file contains configuration information
for the Firewall Toolkit, including the
.B smtpfwdd
proxy.
.IP /var/spool/smtpd
The directory that the
.B smtpfwdd
proxy uses as its root directory.
.SH BUGS
Report bugs to arkenoi@gmail.com or fwtk-users@buoy.com mailing list.
Include a complete
example, explaining what you expected to happen and what actually
happened.  Be sure to indicate the type of system (operating system,
hardware, etc.) you are using, as well as the version of the smtpfwdd
proxy.
.SH AUTHOR
Obtuse Systems Corporation.
.SH SEE ALSO
.BR netperm-table "(5), " rc "(8), " smtpd "(8)"