I am currently getting about 2 to 3 spam trackbacks per hour. I am not approving any of them, but even the notification emails are becoming a nuisance. There doesn't seem to be much I can do about it, and I can't globally stop them (only per post, and I'm not going to change the settings of 600+ posts). So I've decided to ignore them by switching off the notification emails. If you're trying to send a trackback and wondering why it's not appearing, it's because I'm unaware it came in. Sorry about that.
Comments should be fine.