Which free and paid forum software packages have the best spam protection built in? In my experience, MyBB, phpBB, and XenForo, all have good spam protection. However, spammers did manage to get into one MyBB setup I had, after I used the built in protection, and they managed to get into the phpBB setup that I replaced it with. However, this was a lone case. My other domains built on phpBB and MyBB hadn't got even one spammer.