FAQ updates needed

I would like to suggest two changes to the faq.

1/
      Is there a mailing list?

      There are four actually. 

That should read 'five' :-)

2/ 
      Whoa, that's an underscore in _spf.

I assume this section relates to an earlier design, and should be
removed.  However if it is still relevant, maybe a bit more
explanation is needed, as I couldn't find the relevance.

NeilBrown