According to my own experience, the system seems to detect spam as soon as you write too often, around a minute or less when editing your responses...

You can be detected as spam if you go back to your post and don’t change enough characters. It appears that you have to enter a certain number of new characters.

Seems, also, our Spam robots are back - so the level of Spam protection is liable to change... if you can’t post - wait awhile and then (please) come back. Sorry for the inconvenience, but I’ve seen some robot post showing up - when that happens the filter level adjusts.