What I dont understand is that members are registering and posting without being approved? I have ZERO pending members, but several dozen new members? What am I missing?
Silly question, but worth asking: is E-mail Mode also on? Most of those won't work if its set to off and/or if your e-mail server isn't configured right.
Since you mentioned the "Filter Known Spam Domains" can I assume you're using 3.4.07? or did you add that MOD to a previous version?
In either case, did you actually add some spam domains to filter?
It's a on going battle. Mine has setteled down quite a bit. but the More option I added Date of birth and single or not, city, state ect and I set them all to required. the Forum bots have left my forum alone. I still get a lot of hits and traffic at night but don't see any added members or forum posts. Also there is a place on the web to add "All known spam domains" most of them being .RU I would suggest you use that as well. If you have updated the forum to the latest version or have the MODS installed.
just add a custom fiel in registration that says "Do you plan to post illegal stuff?" and only continue when user sets that to "no" while default is set to "yes". Bots will simply not "expect" that and be unable to register. If it's humans that spam there is not much you can do anyways. You can set approval mode but will lose normal members if you take too long with approval.
I one of my forums i have set a "post requirement" for some of the downloadable programs which had lead to excessive spam. Since i have introduced a "point system" so that they require points that are only awarded by staff the spam is gone, the worst spam we have is like "OMG, how do i get points?".