My website is still underconstruction, but i installed forum few months ago. Its full of spamming now. i deleted lots threads, post & banned several peoples but still can't control spamming. what to do to prevent spamming here is a link...all full of spam threads http://forums.fastenglishbd.com/index.php?PHPSESSID=cce9894dd99a50ebf5e2f1b9de9fca67&board=1.0
I think this is Xrumer spam software who did all the spams on your forum check this out http://custom.simplemachines.org/mods/index.php?action=search;basic_search=spam
You can ban IP addresses and also do wildcard bans on some of the addresses but you will always have to manually delete stuff when you run a forum. You can also take some time when you approve new members and look at their IP addresses and names. When they have a Russian IP and a name like "AffiliateMarketer" they are probably SPAM. (unless you are on DP)