Spam add-ons?


We suddenly have a real issue with spam and I wondered if anyone could recommend a free addon, one that ideally stops registrations.

I used to use a great one that stopped country via IP but it was a real drain on the server.

But if anyone has a suggestion for something that would be great.

Btw at the moment we are using the Capcha and not the Q&A but I'm not sure how robust that is.