Re: Unknown mechanisms

On Friday, September 02, 2011 02:12:10 PM Murray S. Kucherawy wrote:
> > -----Original Message-----
> > From: Scott Kitterman [mailto:[email protected]]
> > Sent: Friday, September 02, 2011 11:06 AM
> > To: [email protected]
> > Subject: Re: [spf-discuss] Unknown mechanisms
> > 
> > New mechanisms (unlike new modifiers) can change the SPF result.  If we
> > were to add a new mechanism, then we'd have to bump the version.  If an
> > unknown mechanism is encountered, the correct result is permerror.
> 
> Fair enough.
> 
> I'd like that to be explicit.  As it is now an implementer could decide
> that ignoring unknown mechanisms is simplest (and a common practice, such
> as in DKIM and its friends), leaving the remaining record parsable and
> usable.  Something like "An SPF-aware receiver encountering an unknown
> mechanism MUST return a 'permerror' result" would be good to add in the
> right place.

I've looked over the relevant bits of RFC 4408 and I agree it could be more 
explicit.  Thanks,

Scott K