It appears that my email has gotten in the hands of some scammers with a botnet or something. What do I do?

Suddenly I started receiving a bunch of scam mails (phishing). I suspect some bot or bot-net is involved, because I've received maybe a couple hundred e-mails at the time of writing, all from different (likely auto-generated) senders. With anything from 2-10 emails per day.

The scam is essentially just some phishing, all related to the same topic. I've mostly been able to mitigate it by filtering out mails containing certain keywords or phrases that show up in the scam mails. However, the mails change relatively often (about once a day) so every now and then something gets through, and I'll update my filter.

My question is really if there's any way I can figure out

1. Where this is coming from,
2. How they got hold of my email

So that I can try to go after the root cause / prevent other scammers from getting hold of it.