MyBB Community Forums

Yeah, I thought about that.
Thing is, usually spammers don't FULLY register, as in they don't tend to open the confirmation email.

Then they shouldn't be able to post. If you require email verification they shouldn't be able to post until they have clicked on the link in the email.

StopForumSpam works off of a crowd-sourced database of spammer usernames, emails, and IP Addresses. Sadly some spammers go unreported and may slip through. You can stop automated registrations by adding a captcha (the NoCaptchaReCaptcha is great, but you have to register an API key first) and requiring email verification. Sadly many spammers may choose to register manually and activate via email, then add the account to their spambot. In this case there is nothing you can do other than remove the posts, ban the account and ip address. Whileas you can never completely stop spam, through the usage of databases like StopForumSpam, extra verification measures, and having a good moderation team who is trained on how to deal with spammers you are able to manage spam to where it will not harm the community.