[bitfolk] Whitelist mail by domain

I've just had a brief interchange with a small charity that uses
DigitalOcean for some of their systems. A password-change mail from
their website was binned by my exim instance, for a score of 8.8 given
to it by the Bitfolk SpamAssassin (5.0 of that for coming from Digital
Ocean).

Can anyone suggest how, if at all, I can whitelist mail from that
particular domain in my (Debian) exim4 config, given that I'm using
the Bitfolk SpamAssassin and therefore have no control over it?

Thanks,
Hugo.

-- 
Hugo Mills             | No names... I want to remain anomalous.
hugo@... carfax.org.uk |
http://carfax.org.uk/  |
PGP: E2AB1DE4          |