[exim] Looking for Mail::SPF (2.002) Exim acl example

The older Mail::SPF::Query perl module also included a simple Exim acl
example, the newer Mail::SPF does not. Does someone have an example acl
that might include checking at the HELO, MAIL commands in addition to RCPT
and DATA commands.

I'd also like some options - 'deny' or 'drop'? If a message fails SPF
checking at the HELO or MAIL level, why should I not just 'drop' the
connection rather then 'deny' the message?

Thanks,

Dan Mitton