I'm still working on the spam problem.  I'm back from vacation, so will be deleting spam and banning bad accounts.  Also going to check in with the folks over at SMF to see if a security fix is in the works.  Thus far, SMF has been the better open source board when it comes to fending off spam.  I hate to go to a commercial solution (I really like SMF), so we'll see....

I'm sure you will come up with a solution. My own opinion is to just ignore it. Unfortunately, that isn't always practical.

A suggestion might be to prominently post directions on how to respond / notify the administrator about spam. I do get annoyed when I see comments telling me that the thread is "spam".

Just something to think about, you might want to delete some threads that haven't been commented on for a few weeks. They might be achieved for reference. Their presence though clutters the whole board and makes filtering through what I want to read and have already read, a cumbersome deal. Just a thought.

The problem with ignoring it is occasionally you get people posting things that are NSFW (not safe for work) which can cause hassles for the other members who might be in cubes, etc.  (including myself!).

I don't mind a response saying SPAM since it helps me catch it.  Also, I nuke the entire spam thread any way, so the SPAM comment goes away as well.