What you describe is one of my biggest annoyances too, and very common with contingency recruiters. Luckily, our internal recruiters are fantastic and a couple have taught themselves how to program to be able to carry on introductory talks better!

Stack Overflow Jobs (our job board) also explicitly disallows this sort of behavior. If a first-touch e-mail doesn't list why the person in particular is being contacted, again, I think it's spam.