I can't seem to find (hoping there is) a way to set the tone notification periodic; the phone would make a noise
every let's say minute notifying you that there is a message. I'm sure that there must a system, I mean HTC, Smartphone, it's only silly to think it won't have a simple feature like this.... :\
E: Just found out that it's not possible... D:<
So I found this app:https://market.android.com/details?id=edges.android.reminder&feature=search_result
which (according to a post at Androidphones) should suffice. Hope this helps anyone else.