In <NGBBLEIJOEEEBMEIAPBKAEPOILAA(_dot_)scott(_at_)kitterman(_dot_)com> Scott 
Kitterman <spf2(_at_)kitterman(_dot_)com> writes:
Hidden in   domain-end = ( "." toplabel ) / macro-expand
I raise a warning on that kind of thing now.
Okay, but in that case it's also a real error.  Bye, Frank
Cool.  Then that's one that pySPF doesn't currently catch.  More code to
write.
I wonder, do any implementations catch that one now?
libspf2 only raises a warning.  I think the validator at dnsstuff.com
also raises a warning.
The folks on namedroppers thought it was important to make sure SPF
implementations *NEVER* sent out DNS queries for numeric TLDs.  They
have enough problems with it as is (e.g. that have quite a bit of
hardware/bandwidth dedicated just to handle those requests), and they
don't want new code building on that problem.
-wayne