Some of them just want to post ads (and links) for bogus products.
But it seems like some others just want to irritate you..
Very short Posts that make no sense.. "I much enjoy the topic you posted about"..??.
Maybe you could give the original poster (if he has been a member for 90 days),
the power to police his own thread??
So, if I see a Spam or robo-spam post pop up on one of my threads, I can just delete it,
or 'hide it' until you get some spare time on Sunday night?.
I see obvious spam in my new-post-notify email all the time.
I know you are doing a lot of work, since they are mostly gone by the next morning..
If I had a link (anti-spam link), like the unsubscribe link, that would 'hide' or delete the spam post, it might lower your work load a bit..?.