Sendmail Installation and Operation Guide
SMM:08-55
the sender envelope address tacked on. This allows mail with headers of the form:
From: usera@hosta
To: userb@hostb, userc
to be rewritten as:
From: usera@hosta
To: userb@hostb, userc@hosta
automatically. Howev er, it doesn't really work reliably.
d
Do not include angle brackets around route-address syntax addresses. This is useful on mailers
that are going to pass addresses to a shell that might interpret angle brackets as I/O redirection.
However, it does not protect against other shell metacharacters. Therefore, passing addresses
to a shell should not be considered secure.
D This mailer wants a "Date:" header line.
e
This mailer is expensive to connect to, so try to avoid connecting normally; any necessary con-
nection will occur during a queue run. See also option HoldExpensive.
E
Escape lines beginning with "From " in the message with a `>' sign.
f
The mailer wants a -f from flag, but only if this is a network forward operation (i.e., the mailer
will give an error if the executing user does not have special permissions).
F This mailer wants a "From:" header line.
g
Normally, sendmail sends internally generated email (e.g., error messages) using the null
return address as required by RFC 1123. However, some mailers don't accept a null return
address. If necessary, you can set the g flag to prevent sendmail from obeying the standards;
error messages will be sent as from the MAILER-DAEMON (actually, the value of the $n
macro).
h
Upper case should be preserved in host names (the $@ portion of the mailer triplet resolved
from ruleset 0) for this mailer.
i
Do User Database rewriting on envelope sender address.
I
This mailer will be speaking SMTP to another sendmail -- as such it can use special protocol
features. This flag should not be used except for debugging purposes because it uses VERB as
SMTP command.
j
Do User Database rewriting on recipients as well as senders.
k
Normally when sendmail connects to a host via SMTP, it checks to make sure that this isn't
accidently the same host name as might happen if sendmail is misconfigured or if a long-haul
network interface is set in loopback mode. This flag disables the loopback check. It should
only be used under very unusual circumstances.
K
Currently unimplemented. Reserved for chunking.
l
This mailer is local (i.e., final delivery will be performed).
L
Limit the line lengths as specified in RFC 821. This deprecated option should be replaced by
the L= mail declaration. For historic reasons, the L flag also sets the 7 flag.
m
This mailer can send to multiple users on the same host in one transaction. When a $u macro
occurs in the argv part of the mailer definition, that field will be repeated as necessary for all
qualifying users. Removing this flag can defeat duplicate supression on a remote site as each
recipient is sent in a separate transaction.
M This mailer wants a "Message-Id:" header line.
n
Do not insert a UNIX-style "From" line on the front of the message.