why my valuable posts goes under spam?

When ever i write a big post it says sorry you are spamming the site.

my valuable time goes waste!

I think it says that if your post includes a link, or when you have posted on the same thread before.

I have checked twice i did not post simultaneously on the same post twice i answer the question or some times when i write a good quality post of owver 100 words it says Do not spam and thats why i will never again write a big post.

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