Every so often, I get an email that looks like:
While conducting a search for our client we came across your resume and it appears to be a good match for this opportunity. Blah blah fast-paced blah blah great benefits blah blah and so on.
Using the word "candidate" is not only presupposing, but a sign of laziness. Even the male enhancement spammers can personalize their messages. I'm sure the recruiter will have his pick of top talent with emails like this.
I think I'll reply with the following.
Dear [Recruiter Name],
Thank you for getting in touch about the [Position Name] offer with [Company Name]. Unfortunately, I'm busy on a project that will generate automated responses to mass mail job offers. I'm still working out a few bugs.