@amy It's likely that you've ended up in some poorly-put-together 'leads database', misclassified as a supplier of something. My PDF hosting site had a bunch of a company's brochures on it, and ever since then I've been getting similar e-mails at its contact address for those industries.
The e-mails themselves could be either legitimate or attempts at a scam. But they're almost certainly pulling from some crappy industry address list or other.