I have a mysterious situation where the cache is not sorting correctly. I moved the point where I do the cache sort way down to just before I save it. I hope this helps. Wouldn’t you know that I haven’t received any spam since I made the changes. I hope that the sort order fixes itself.
I added DNSBL support. Right now it is turned on all the time and I always check the IP at several popular email spam black hole checkers. I am not sure how well this works with comment spam. After all email spam is different than comment spam. I should catch a few this way as comment spammers are probably related to email spammers.
I reject disposable email addresses from a list of disposable emails I compiled by searching forums. The list is probably older and I would like to find a reliable public list that I could use to update things from time to time. Right now this is just a test. I expect some user to claim that I am rejecting legitimate users by rejecting disposable emails.