The problem I’ve had with recruiters is not so much the Spam, but that they've nearly always been an utter and complete waste of my time, even when I meet with them face-to-face. I’m a UX Designer and almost all of the recruiters I’ve dealt with have no clue what that term means. Some of them insist on sending inappropriate job offers to me. This includes developer (coding) jobs, DB Administrators, or positions as System Architect (because sometimes Senior UX Designers call themselves UX Architects). I explain to them that there is a difference between a UX Designer and a UI Developer but they give that a blank stare. In short, there needs to be some attempt by recruiters to try to understand what roles they are trying to fill. Otherwise, to them, people like me are just pieces of meat.
It’s even worse with recruiters for contract work (and up until recently, that was a lot of UX work, since after a product was designed and shipped, there wasn’t any reason to keep a UX designer around — this has changed over time to become a more permanent role.) In the case of a contract, they are so anxious to get it taken care of that they actually pitch rates that are too low. This is also because their fee is not necessarily based on the hourly rate I charge, but instead they charge a standard surcharge on top of my rate, forcing them to lowball their quotes.
All in all, I can safely say that I’ve had close to zero success with recruiters. I suspect that for others, their hit rate is probably lower than they’d like.