I have it set to 180 but some spammer registered and I think he replied in like 30 topics in under 15 mins.
Unfortunately I erased this guy and his posts from within the CP, but I'll try to make a 'print screen' the next time something like this happens.
P.S. Is the edit feature fully safe now? Before even with an edit time limit of 5 mins users could edit their messages indefinitely as long as they simply opened the edit page within those 5 minutes...
