The "sendmail-5.65c+IDA-1.4.4.1-ident.patch" file contains the modifications
needed to add support of RFC931/IDENT/TAP (from now on called IDENT) in
Sendmail. It uses the IDENT protocol to retrieve the identifier associated
with a TCP/IP connection if someone initates a connection to the SMTP port.
(And the machine the connection was initated from has a server running that
implements this protocol. One such server can be FTP'd from the machine
"ftp.lysator.liu.se" in the directory "pub/ident" as "pidentd-???.tar.Z".

It will put the identifier retrieved into the "$F" macro so that it can
be included at an apropriate place in the "sendmail.cf" configuration file.
For example, we are using the following entry for the "HReceived" line:

	HReceived: $?sfrom $s $.by $j $?r with $r$.
	          ($v/$Z/Lysator-3.1) id $i; $b $?F
	          (rfc931-sender: $F@$S)$.

This will add a comment line to the "Received:" line if it can retreive
an identifier.

The identifier will also be included in the "syslog" log file. An example
of how it might look like is:

Jul 29 08:17:43 lysator sendmail[10169]: AA10169: from=<owner-operlist@eff.org>, size=1239, class=0, received from daemon@eff.org (192.88.144.3)

This patch should work on plain Sendmail-5.65c with some small hand editing
(the line numbers might now match exactly).

Peter Eriksson <pen@lysator.liu.se>, 30 July 1992