For those following Sender based authentication - a question

[Dan Jenkins]

I was a bit too quick on the reply, the HELO in the mail header is from 
the first mail server which accepts the message. Subsequent hops don't 
change the initial HELO. However,  I do have mail servers which have to 
rewrite headers and provide a specific domain in a HELO for mail to be 
accepted. (A certain ISP requires this.) Some of my mail relays write 
the headers after cleaning up messages and then send them to internal 
mail servers. They show a fresh HELO from the gateway mail server. And, 
as someone mentioned, HELO is frequently (usually?) wrong. One (all?) of 
the Outlook clients do not send a valid HELO in any event (they don't 
use a FQDN and just use the system name). The HELO does include the IP 
number of the sender (presuming it hasn't been rewritten along the way), 
so, perhaps that is what the FTC was intending - ignore the HELO name 
and presume the HELO IP# to be the author. It still doesn't work, but it 
is not as unreasonable as my first knee jerk reaction was.

-- 
Dan Jenkins (dan at rastech.com)
Rastech Inc., Bedford, NH, USA --- 1-603-206-9951
*** Technical Support for over a Quarter Century