Do you mean that it would count back 24hrs from the latest message and check the total number of messages sent and then either allow or deny?

Let's say i send a message on 23-05-13HIDDEN@0 hrs, would it check the total number of messages sent since 22-05-13 @ 14:00 hrs and then either allow or deny. Is this how it works?

If yes, will this logic work even when surgemail is restarted between 22-05-13 14:00hrs and 23-05-13 14:00 hrs? 

Thanks
Vinesh