I'm well aware, but a bayesian spam filter probably is not. If you look up lists of words most likely to trigger spam filters, "cheap" will be in every one of t

I'm well aware, but a bayesian spam filter probably is not. If you look up lists of words most likely to trigger spam filters, "cheap" will be in every one of them. I can't say that is what's happening here but it seems plausible at least. I would also argue that spam messages aren't really trying to convince you something is low quality, it's precisely the low cost aspect that they're to convince you of even if the product is actual low quality. I'm sure there's other companies with cheap in their domains/headers, but none stand out and I would have no idea if they depend on SEO anyway.