HELO vs. MAIL FROM

Hi,

I'm still thinking about the proposal to verify
the host name given in HELO/EHLO instead of 
MAIL FROM sender envelope address.

I agree on two details:

- It is a good idea to consider the sending MTA as 
  an originator of an error message if the sender
  envelope address is empty (<>) and to use the 
  given host name (or it's domain part?) instead for the 
  RMX lookup.


- It does not break any forwarding mechanism.


But I still believe that the latter one is not an
advantage, but just a consequence of the malfunction. 

I'll give a real world example:

This particular message is sent with a sender envelope
address  <[email protected]>, because I am the originator
and initiator of the message. correct.

But it is delivered to the world through my ISP's relay
which's host name is sklave3.rackland.de, which is also
used in the EHLO command.


So if you query the RMX record for this name, you'll get
the RMX record for rackland.de or sklave3.rackland.de.

This record will confirm that the authority of rackland.de
authorizes this machine to be sklave3.rackland.de.

But how do you want to verify that this machine is authorized
to deliver mails from danisch.de  if not with the envelope sender
address?

Hadmut