Other than relaying mail via SMTP or LMTP, the
sendmail program does not perform the actual
delivery of mail.[25] Instead,
it calls other programs (called mail delivery
agents
[26]) to perform that service. Because the mechanics of
delivery can vary widely from delivery agent to delivery agent,
sendmail needs a great deal of information about
each one. The sendmail
M
configuration command defines a mail delivery agent and provides the
information that sendmail needs.
V8.13 sendmail has made four changes regarding delivery agents, three of which are described here and two of which are described in the specified sections:
The #error
agent can
now return a
$@ quarantine
with a reason (Section 11.1.2.6
[V8.13]).
Connections caching for the LPC delivery agent (Section 6.1 [V8.13]) is now provided.
The new F=B
delivery agent flag
strips all leading backslashes (Section 20.1.1
[V8.13])
The F=f
flag has been removed from
the defaults for
local_lmtp
(Section 20.1.2
[V8.13])
The new F=W
delivery agent flag
causes
persistent host status to be ignored for an individual delivery agent
(Section 20.1.3
[V8.13])
The F=s
(20.8.43[3ed]) delivery
agent flag
causes sendmail
to dequote the
recipient’s address before passing it to the
selected delivery agent. Dequoting causes all quotation marks
(“) and all leading backslashes
() to be removed. But when a lighter touch is
needed, you may use this new
F=B
flag instead,
which just removes all leading backslashes. For example:
"\user"@relayhost with F=s becomes user@relayhost "\user"@relayhost with F=B becomes "user"@relayhost
Note that because F=B
is a subset of
F=s
, you are discouraged from using both flags at
the same time.
Prior to V8.13, the local_lmtp
feature
(4.8.19[3ed]) set the default
LOCAL_MAILER_FLAGS
(20.5.6.2[3ed]) to
F=PSXfmnz9
. Beginning with V8.13, the
F=f
flag (20.8.24[3ed])
is no longer set as part of that default. Recall that if
sendmail
is run with a -f
command-line argument (15.7.23[3ed]), and
if the F=f
delivery agent flag is specified, the
A=
for this local delivery agent will have the two
additional arguments -f
and $g
inserted between its argv[0]
and
argv[1]
.
The HostStatusDirectory
option (24.9.52[3ed])
defines
where
long-term host status should be maintained. If you prefer a
particular delivery agent to ignore that status, you may do so by
defining this F=W
flag. When defined, it acts as
though the HostStatusDirectory
option were undefined
for that particular delivery agent.
54.159.186.146