Sometimes, as a recruiter, we see a candidate who doesn’t match the specifications exactly, but whom we feel offers unique strengths that make them worth including in the search process. You may agree, and find that the candidate opens up new possibilities you might not have previously considered. On the other hand, you might not.
If that’s the case, don’t waste your time (or theirs) interviewing a candidate that you truly don’t believe is a fit for your role, no matter how well recommended they come. Candidates know when they’re being asked perfunctory questions, and will resent the lost time when they realize you weren’t interested in the first place. Why risk your reputation?
Judge for yourself whether it’s worth your time and theirs, and follow your instincts.