Sendmail Installation and Operation Guide
SMM:08-47
$n The name of the daemon (for error messages). Defaults to "MAILER-DAEMON".
$o (Obsolete: use OperatorChars option instead.) The set of "operators" in addresses. A list of
characters which will be considered tokens and which will separate tokens when doing pars-
ing. For example, if "@" were in the $o macro, then the input "a@b" would be scanned as
three tokens: "a," "@," and "b." Defaults to ".:@[]", which is the minimum set necessary to
do RFC 822 parsing; a richer set of operators is ".:%@!/[]", which adds support for UUCP,
the %-hack, and X.400 addresses.
$p Sendmail's process
id.
$q Default format of sender address. The $q macro specifies how an address should appear in a
message when it is defaulted. Defaults to "<$g>". It is commonly redefined to be "$?x$x
<$g>$|$g$." or "$g$?x ($x)$.", corresponding to the following two formats:
Eric Allman <eric@CS.Berkeley.EDU>
eric@CS.Berkeley.EDU (Eric Allman)
Sendmail properly quotes names that have special characters if the first form is used.
$r
Protocol used to receive the message. Set from the -p command line flag or by the SMTP
server code.
$s
Sender's host name. Set from the -p command line flag or by the SMTP server code.
$t
A numeric representation of the current time in the format YYYYMMDDHHmm (4 digit
year 1900-9999, 2 digit month 01-12, 2 digit day 01-31, 2 digit hours 00-23, 2 digit minutes
00-59).
$u The recipient
user.
$v
The version number of the sendmail binary.
$w The hostname of this site. This is the root name of this host (but see below for caveats).
$x
The full name of the sender.
$z
The home directory of the recipient.
$_
The validated sender address. See also ${client_resolve}.
${addr_type}
The type of the address which is currently being rewritten. This macro contains up to three
characters, the first is either `e' or `h' for envelope/header address, the second is a space, and
the third is either `s' or `r' for sender/recipient address. Notice: for header addresses no dis-
tinction is currently made between sender and recipient addresses, i.e., the macro contains
only `h'.
${alg_bits}
The maximum keylength (in bits) of the symmetric encryption algorithm used for a TLS con-
nection. This may be less than the effective keylength, which is stored in ${cipher_bits}, for
``export controlled'' algorithms.
${auth_authen}
The client's authentication credentials as determined by authentication (only set if success-
ful). The format depends on the mechanism used, it might be just `user', or `user@realm', or
something similar (SMTP AUTH only).
${auth_author}
The authorization identity, i.e. the AUTH= parameter of the
SMTP MAIL
command if sup-
plied.
${auth_type}
The mechanism used for SMTP authentication (only set if successful).