! line
Deliver-by specification V8.12 and later
Beginning with V8.12, sendmail
supports the DELIVERBY SMTP extension (defined by
RFC2825). If the DeliverByMin
option (DeliverByMin on page 1003) was defined
with a positive value, a BY=
equate can follow the SMTP MAIL From:
command for
inbound email. The BY=
equate defines the window of time
during which the message should be delivered. That
equate’s time value can optionally be followed by a
flag that states what to do upon delivery (an
r
flag), or
upon delivery failure (an n
flag). There can also be a flag that
advises sendmail to trace
delivery (a v
flag). The BY=
information is saved in the qf
file on an !
line:
!flag time
Here, the time
is the time
specified by the By=
and the
flag
is a 1-byte
integer that encodes a value of 1 (notify the sender
upon delivery), or 2 (return the message if it
cannot be delivered in time). Additionally, the
flag can be OR’d with a 0x10
(trace the delivery).
This !
line appears
for inbound mail only, and appears only if you have
configured your mc file to
define the DeliverByMin
option with a positive
value.
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