That's a very effective idea that works for someone who has little to no skills in SEO or programming. Of course, his "tool" will do next-to-nothing for spammers, they already know that 80%-90% of their email databases are dead emails or fakes. That's why they build lists of millions of emails.
I think even 95-99% of their database + 99.999% of the e-mails they send just get into bulk mail folder