If this perpetual check is as true as you say it is then you will still have to wait fo your opponent to move. What's the time control per move, one, two or three days?
I've never heard no such thing as a, "3 fold repetition checkmate?" If these perpetual moves are repeated three times the game will be drawn but depending on the time control per move this could take some time.
In correspondance Chess how do you get an automatic draw triggered? I have a guy out played me but I have him in perpetual check and there is nothing he can do. I have offered draw but no responce. I can keep him in check until 3015 lol How do you get the 3 fold repetion checkmate to be called in correspondance or should I write a administrator?