It seems to me that these "mature content" emails are part of their automatic warning systems. They detect certain words on your pages, and send the emails out. Do you have any evidence that a real person has reviewed your pages, or do the emails just look like a templated response?
You may be right. It looks like it could very well be a templated warning. The message said they would *automatically* detect updates to the offending page(s). So maybe it's an automated detection of a naughty word. And maybe the bot will revisist after three days to see if the naughty word has been removed. And maybe if it still finds an offending page it will maybe get referred to a human for review. That's a lot of maybes, but maybe. Chocolate fetish, baby.
what if you have a site like this? A: sitename.com <- uses adsense, content is ok B: sitename.com/xxx/ <- doens't use adsense, but content is adult Is this ok or not? Also, if A links to B, could that be a problem? or if A doesn't link to B? also what happens if there are more users under the same domain?