Even if the reverse-path has been rewritten to reference an appropriate
mailbox, the owner of the mailing list is likely to be uninterested in the
sender's vacation plans. After enough of these, the owner may even
manually pause or remove the sender from the list, resulting in the same
effect.
If the reverse-path has been misconfigured to reference an inappropriate
mailbox (eg, list-request(_at_)domain) then this might even happen
automatically. This is *designed* to happen automatically with mailing
lists that use VERP and similar proposals:
VERP isn't well-designed then. a recipient-unique envelope return address
is useful, but it's unwise to expect that every message sent to that
address is a nondelivery report - there is absolutely nothing in the mail
specifications that says that only nondelivery reports should go to that
address.
| The VERP extension implements
| a way of automatically identifying undeliverable mail recipients,
| even when non-delivery reports originate from mail systems that do
| not implement delivery status notifications
Even outside the list world, there are scenarios where sending to the
reverse-path is inappropriate. EG, when the Sender/From construct is
actually used, the notification is returned to the Sender instead of the
From parties.
That's a bug in RFC 822. Nondelivery reports should always go to the
Return-path/MAIL FROM address, NEVER to the Sender address. The
contents of the Sender field aren't even required to be a legal address.
I might be using a terminal or kiosk with a reverse-path referencing the
mobile account, but with From pointing to my master mailstore. I may not
see the notification messages for several months, if ever.
In this case only Sender should point to the mobile account, and
return-path/ MAIL FROM should point to where you want to receive reports.
These examples are all really beside the ultimate point, however:
out-of-office notifications are an application of the messaging network
and not in-band management messages, so they really should use the headers
rather than the envelope.
That's precisely the reason that the MAIL FROM address is exposed in the
message header as return-path - so the address can be used for automatic
responses that are generated after the message leaves the transport/delivery
system.
Keith