What if EHLO/HELO check fails?

Another detail:

What do we do if the RMX check on the given HELO name
failed? Do we proceed and see, whether the MAIL FROM 
might succeed or do we declare the whole SMTP session 
as a fake? Or do we not care at all and say: Just determine
whether HELO and SENDER are ok or not and let the 
MTA admin do with it whatever he wants?

Hadmut