Re: HELO vs. MAIL FROM

On Wed, Oct 22, 2003 at 02:49:38PM -0400, Alan DeKok wrote:
> 
>   We look at the domain for the host name, and ask that domain about
> the IP address which claimed to be a host in that domain.
...
>   We strip off the machine name, and only the machine name.
> 
>   e.g. I have a machine 'giles.striker.ottawa.on.ca'.  I've had
> bounces from idiot mailers, because they claim that 'ottawa.on.ca'
> doesn't have an MX, and doesn't know about 'striker.ottawa.on.ca'.
> 
>   We can assume that the name in the EHLO/HELO is a host name,
> followed by a domain.  We can make NO assumptions about that domain.


So we can assume that the EHLO name consists of at least three
components?    host.domain.com ?

Or just two?   Would it be allowed to name my relay just
danisch.de ? Many domains give their domain name an A record
and have web servers at the domain name without "www." 

If the machine is named like danisch.de (=domain name without host
name) the lookup would fail in general.


So as a general requirement for things to work we'd state that
a EHLO name must always be of the form

  hostname.DOMAINWHERETOLOOK


where hostname is exactly one component and
DOMAINWHERETOLOOK consists of at least two?

regards
Hadmut