The sendmail program
uses the $r sendmail macro
($r) to store the protocol used when
sendmail first received a mail message. If the
message was received by using SMTP, that protocol is
smtp. Otherwise, it is NULL.
The
sendmail program uses the $s
sendmail macro ($s) to
store the full canonical name of the sender's
machine.
The
sendmail program uses the $_
sendmail macro ($_) to
store RFC1413 identd(8) information and IP
source-routing information.
When sendmail creates a qf
file, it saves the values of the $r,
$s, and $_
sendmail macros in lines that begin with
$.
The form of the $ line in the
qf file looks like this:
$Xvalue
${XXX}value
The $ must begin the line, and the
sendmail macro's
single-character name (the X) or
multicharacter name (the
{XXX})
must immediately follow with no intervening space. The
sendmail macro's name is
followed (again with no intervening space) by the value of the macro.
If value is missing, the value given to
the macro is NULL. If the macro name and
value are missing, the macro
\ is given a value of NULL. If both are present,
the macro whose name is specified is given the value specified
(value).
There can be multiple $ lines. The
sendmail macro names to be stored in the
qf file are listed in the
$={persistentMacros} class ($={persistentMacros}).
