I have been posting a TON of pro material and at one point received one of those auto responses. It said my ability to post has been suspended for 24-48 hours due to excessive posting. I had posted no more than any other day in the past month and a half. I assume someone on my list didn't like what I was posting and flagged me. However the next day I went right back to it. No further issue to report so far.
Half the country hates my business, the other half my hobby.