Not sure if this forum software supports stricter validation process, otherwise have a pre-signup process before the actual forum signup for new members, a 2-step process -- This would then require 'Valid' home address, phone number, additional phone number (mobile/cell - optional) and zip code. Then allow 24 hours for process and the first 30 posts can only be posted in a "New Members Support and Pre-Sales Questions Forum" with a St(r)icky- Topic explaining why -- (Spammers and Trolls).
Also, The link to the forum is too clearly labelled as;' Cakewalk Forums', {uh oh} what about being a little more discreet -- List the link to these forums under another link-header >> {next Page} >> List of Options and oh yeah included in that list is a more discreet title = '{Title}-Signup' (NOT titled: Cakewalk Forums) however, only existing and new customers who have purchased Cakewalk product(s) will receive Emails with a more direct link.