I post over 1k auctions per day for the past year or so and have never had a problem. However i play the AH alot so i believe it is key to post a variety of different things along with buying off the AH. It looks very suspecious when a person posts 300+ auctions a day of nothing but herbs/ore. However it looks pretty legit if its a mix of glyphs, herb, ore, bars, gems ect...
Edit: Forgot to mention that if you have a massive amount of product you need to move find a private buyer. When i have 200+ stacks of ore or something i need gone in a day i will spam trade looking for a bulk buyer.