Attempted fraud with craigslist listing, what would you do? :)?

I posted an add on craigslist, and someone claiming to be from the UK contacted me via email pretending to be interested in my item. I didn't realize this person was from the UK until I said I would accept a cashiers check from them, thinking it was from a person that lived here locally. Anyways, I caught their scam, (they don't know because they keep emailing me concerned about the money wiring transfer information...haha) They want me to wire the excess funds to the supposed shipper and all this other information. You could tell the check was totally fake. Anyways, my question is that they still think I'm going to send them money.... I felt like saying back I know about your little scheme you little ******, or a big picture of a hand flipping the bird. OR would that be a bad idea and just ignore/block future emails? I feel like saying something mean. I already reported them to craigslist, turned the fake check into my bank telling them it was fake, and some filled an online complaint form with the information they gave me.... what would you do? I know now to NEVER post my email in craigslist and now know what to look out for.