Greg Connor wrote:
[snip]
Another point to ponder. If we decide that there are cases
where we want to validate Sender: and we CAN'T validate From:
(such as something passed by a list)... would it also be
useful to some folks to publish rules like "Always validate
From: and do not use Sender: to override?" This might give
PayPal and friends a way to send messages from their "Role account"
which should *never* go to a mailing list, and that particular From:
address would always be checked, even if we default to
checking Sender:
most of the rest of the time.
[snip]
Caller ID includes a mechanism for doing exactly this. Sending
organization include a <directOnly> element in their DNS information
that indicates the domain only sends mail directly to end users and not
through mailing lists.