You can do a significant number of hours per day, but if you mine in Uldum for 18 hrs, someone at some point is going to report you. Just move around. If you go afk to go to the grocery store, let it go in uldum... when you get back, go somewhere else.
(Uldum is hugely over-botted and people report people like crazy on my server).
Luckily, never been suspended for that.