The -N command-line
switch causes sendmail to append the DSN NOTIFY
command to the ESMTP RCPT command. For example:
RCPT To:<friend@other.site> NOTIFY=SUCCESS
Here, sendmail is requesting that the other site
return notification of successful delivery.
The -N command-line switch also causes
sendmail to behave as if it got the NOTIFY
command when producing a local bounce message. That is,
-N affects the other sites'
behavior on SMTP mail, and the local site's behavior
on local delivery.
Should the message be successfully delivered by a host that
understands DSN, or by the local host, a return message will be sent
to the sender. If either site is running V8.8 or above
sendmail, that return message will look (in
part) like this:
Date: Fri, 13 Dec 2002 08:11:43 -0800 (PST)
From: Mail Delivery Subsystem <MAILER-DAEMON>
Subject: Return receipt
Message-Id: <200212132144.f21IuJf8029510@other.site>
To: <you@your.site>
MIME-Version: 1.0
Content-Type: multipart/report; report-type=delivery-status;
boundary="f21IuJf8029510.834702270/other.site
Auto-Submitted: auto-generated (return-receipt)
This is a MIME-encapsulated message
--f21IuJf8029510.834702270/other.site
The original message was received at Fri, 13 Dec 2002 08:11:43 -0800 (PST)
from other.site [204.255.152.62]
----- The following addresses had successful delivery notifications -----
friend (successfully delivered to mailbox)
The -N command-line switch tells the NOTIFY
command what to include and thus tunes how notification will be
handled. The form of the -N command-line switch
looks like this:
-Nnever
-Nkeyword,keyword,...
The first form sets NOTIFY to be NEVER, meaning send no notification.
The second form tells NOTIFY to specify notification based on one or
more of three possibilities:
- success
-
The success keyword tells
sendmail to ask for notification of successful
final delivery.
- failure
-
The failure keyword tells
sendmail to ask for notification if the message
fails to be delivered.
- delay
-
The delay keyword tells
sendmail to ask for notification if the message
is delayed for any reason.
These keywords can be listed after the -N to set a
combination of notification requests. For example:
-Ndelay,success
This tells sendmail to ask for notification if
the message is successfully delivered or delayed but not to get
notification if the message fails.
If an unknown keyword is listed, sendmail prints
the following error message and ignores the bad keyword:
Invalid -N argument
If the -N command-line switch is omitted,
notification policy is left to the other site. The usual default is
failure (and possibly delay).
On the local machine, sendmail acts as though
both failure and delay were
specified.
