How can i detect spam post on steemit?

some months ago i create my bot and that bot was use to resteem people posts but suddenly bot get mark as spam without any proper reason. But after talking to people i find out why because it resteem spam post of someone else but still not sure or maybe because upvotes of other accounts.
Now after few days after my exams, i will be launching new bot with more features but what if this bot resteem someone spam post and boom mark as spam again.
There is anyway that i can detect if it's spam post? by looking at downvotes?

Thanks in advance for making time and replying to this post in order to help me.