Re: HELO vs. MAIL FROM

On Wed, Oct 22, 2003 at 12:02:30PM -0500, Gordon Fecyk - Home wrote:
> 
> * If not, or if non-participant, or if null sender, check HELO'd hostname to
> see if it's allowed to send mail for itself.  If so, accept the mail.  If
> not, bounce it, tag it, or do something else.
> 
> It's a little weaker than purely authenticating against MAIL FROM, and it
> would allow some spam through, but it would clearly point the finger at
> who's accountable - the admins of the server that HELO'd itself.  And it
> would allow .forward.


Two questions:

- Where do we look for RMX/SPF/DRIP/DMP? Do we look at the full 
  hostname or do we cut off the hostname?

  Example: HELO sklave3.rackland.de

  Do we search in the DNS zone of sklave3.rackland.de or 
  rackland.de? Or do we rekursively descend until we have
  2 (or 3 for e.g.  co.uk or com.au) remaining domain components?


- Verifying the EHLO name only _is_ an open door for spamming. It
  does allow identification, but not blocking. 

  What do we do? 

    - Yes, we do it.
    - No, we don't want it.
    - Nice, it's the recipient's decision whether or not.
    - Nice, it's the envelope sender domain's decision whether 
      or not (I'd propose to have a special entry in the RMX 
      record which tell's whether or not).


Hadmut