Newbie questions

Hi,

I've just started using greylist on my exim4 MTA. I have come across the
following situation:

1. Spammer sends spam and is greylisted.
2. Spammer keeps sending spam and is eventually whitelisted but spam is
caught by spamassassin and rejected.
3. spammer sends more spam which is caught by spamassassin and rejected.

Is there any way form within exim of removing the corresponding triple
from the whitelist+greylist when (2) happens.

I'm sorry if any of this is naive or obvious, but I've been thrown in at
the deep end setting up and running an MTA a couple of weeks ago.

Bernard