Content filtering is only for inbound domains or users. However, We're actively putting together a solution that will operate at the spool level that will be able to apply more "routing" based behaviors to the email and it will function for ANY email that hits the spool. This should cover some huge requests we've gotten from customers to allow them to better control the routing of messages on their server. It will function very similar to content filtering. Hoping to have out there soon stay tuned!

(These new changes would accomidate this particular scenario especially if you knew the common misspellings of the email and compiled them into a list)