The bad news is that the new feature we have just licensed -- anti-spam filtering -- will probably require some re-engineering of how we handle incoming email in order to actually have it work. The devil, as always, is in the details of implementation. :-)
I'll say this in Fortinet's defense -- their box does a heck of a lot of useful stuff, and it's quick on its feet. But the licensing has been a pain in the ass, and getting it to do the little things we need it to do (like generating truly useful firewall logs) has cost a lot more money then we were originally told.