F=%
Hold delivery until ETRN or -qI or -qR or -qS V8.10 and later
Ordinarily, outbound mail is dispatched as soon as it
is handed to sendmail. There
are times, however, when mail should not be sent
until it is asked for. Consider the typical ISP.
Clients who connect over dial-up lines are not
necessarily connected when mail arrives for delivery
to them. The F=%
delivery agent flag has been added to prevent
sendmail from trying to
discover if there is a connection.
The F=% delivery
agent flag, when set, prevents immediate delivery to
destination hosts. Instead,
sendmail queues all messages.
Each destination host must then request delivery
using the ETRN command (Process the queue via ESMTP ETRN on
page 433) after connecting. One way a client can
give the ETRN command is by using the
etrn.pl script supplied in
the contrib subdirectory of the
source distribution.
The local administrator can also cause delivery to
occur manually for specific clients with any of the
-qI, -qR, or -qS command-line
switches (Process by identifier/recipient/sender:
-q[ISR] on page 431). Note that a standard queue run (as
with -q) will not
send messages that have been deferred because of
this F=% delivery
agent flag.
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