Good form rejected as spam

Hi, I am having a weirdly opposite problem from most regarding spam.

I have an application form for a grant that most users had no trouble with. One user, however, had hers rejected with the error message “your application answers look too much like spam and cannot be submitted at this time”. She sent her application via email and I inserted her text into the fields, hit the submit button, and got the same error message.

I am wondering what the criteria would be that would have caused this. Her application was very professional, and had no concerning words or phrases. It was longer than the others that were accepted, but no obvious other difference.

What are the criteria that are being checked that can cause this specific message?

Thanks