$c
The hop count All versions
The $c macro is
used to store the number of times a mail message has
been forwarded from site to site. It is a count of
the number of Received:, Via:, and Mail-From: header lines in a
message.
The value in $c is
not used by sendmail. Rather,
it is made available for use in configuration-file
header-line definitions. When calculating the hop
count for comparison to the MaxHopCount option (MaxHopCount on page 1046)
sendmail uses internal
variables.
$c is transient. If
defined in the configuration file or in the command
line, that definition can be ignored by
sendmail. Note that a
$& prefix
is necessary when you reference this macro in rules
(that is, use $&c, not $c).
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