Buddypress Private Message Spam

I am still having some (but much fewer) issues with private message spam through Buddypress. I have verified that CleanTalk is activated to protect from buddypress message spam in the advanced settings. Is there anything else I can do to prevent the private message spam without removing or reducing the ability for my users to send private messages?

Very pleased with the CleanTalk premium plugin overall. It has drastically reduced the number of spam issues I am dealing with.