Great mod, but...
I activated just the stopforumspam to prevent spammers registration, ip check , email check and username check all enabled and spam-o-matic blocked some regular registration because a user set the username, for example, "John" and it is included into the stopforumspam database, but not the chosen email or ip, so why isn't there a combined check (ip AND email AND username = SPAMMER)?
Now I have just to disable ip check and username check and keep just the email check.

turn off the username part of it only I find it does block normal user as well

I agree. Leave the email and IP checks enabled.

As i wrote above, now I keep just the email check, 'cause also regular IP are banned...

IPs have to be used by spammers to get into the SFS database. If a user gets a spammer IP address from their provider, they should contact their provider to get a new IP address.

Here in Italy (and I guess for other countries) most of internet connection get a dynamic ip address, so it could be easy to get a banned IP, but IMHO this mod could be improved by a multi check IP/email/username, I also own a phpBB forum and use this little mod to prevent spammers, and it perform this multi check that works very well.

Yes, thats a good point. I think its also important to take into the equation how many times an IP address has been used by spammers.

I installed this and tested it by registering with a fastmail.fm email address, and was blocked as a spammer. But of course I am not spammer, but it seems this mod thinks fastmail addresses are automatically spam? There may be many legitimate people with a fastmail address, who won't be able to register at my site because of this mod. How do I work around this?

edit: Okay, maybe it wasn't the email address. I tried it with a different one and still couldn't register. It seems my username was blocked??? It was a common first name: Warren. And yet I could not register with it. That doesn't seem workable.

It works well if you use just the email check

is there a way to make it work with the blogs? I dont see an option to kill the spammers that are blogging.