Every form submission, in the person's own words, with where they came from. Label each one so tests are judged on good leads, not just more leads.
“Hello, I have a business partnership opportunity for your company, please contact me at once.”
“Buy high quality backlinks for your site, cheap packages available.”
The AI labels every lead. “Needs review” means it was unsure, so a person decides; anyone can change any label. The AI reads the answers only, never names, emails or phone numbers.