I find the spam filter options hard to understand. I would be nice to have an
explanation of the process.
Like: 

"A entry has been sent to the system. If it has a spam score larger than (a) it
is rejected right away. (Is it deleted then??) If it has a spam score lower than
(b), it is kept, but maybe not displayed and a message is sent to the admin. If
it has a spam score lower than (c) it is kept and displayed (and also a message
is sent to the admin)."

or so.