Re: Sender header?

[prj@po.cwru.edu (Paul Jarc)]

Stainless Steel Rat <ratinox@peorth.gweep.net> writes:
> * prj@po.cwru.edu (Paul Jarc)  on Thu, 24 May 2001
>| By your interpretation, the RFC is requiring that every machine that
>| sends mail must be usable in a recipient address - i.e., the MX (or A)
>| for that name must be configured to accept mail addressed to that
>| individual host.  (Otherwise, user-login-name@system-name wouldn't be
>| a mailbox of the originator of the message.)  Do you think the authors
>| really intended to require this?
> 
> Yes, that is exactly what I think.  A records are required for all machines
> on the Internet that have anything to do with mail, and MX records should
> exist for all such hosts.

But your interpretation requires more than that.  It's not enough just
to give random-sending-host.domain.com an MX record pointing to
mail.domain.com - mail.domain.com must also accept mail explicitly
addressed to random-sending-host.domain.com, even if it would
otherwise only accept mail addressed to domain.com itself, because you
would put random-sending-host.domain.com in Sender, and Sender must be
a mailbox of the person who sends the message.

Where does 2822 say that Sender must identify the host used to send
the mail?

> Proper mail handling depends on that being the case.

What breaks when Sender does not identify the host the mail was sent
from?

> If your host has neither A nor MX records then it is not configured
> correctly.

Right, but the A and MX records aren't the problem.


paul