@julian hope you can do both soon enough. It was very frustrating not being able to post references. I think I've never spammed in my life, yet those robots are not much better than humans in filtering me out. Maybe this is just a very personal frustration thing, but well, anyway, here you go with some (more) feedback.
- Improve the message about the spam. Advise people to remove links maybe. (You're probably aware of this general idea of no intro stage)
- Set a threshold for adding up to 1 or 2 links at least (like discourse do), without akismet getting to it.