In My view, Recruitment is part of both Marketing & HR.
Working on Manpower planning ,finalise Job description for any certain post, decide the competencies for any post,then shortlisting of Resumes on the basis of Job Description comes under HR activity.
Calling the candidates, convince them for the existing post, bring them for company's decided criteria and budget,comes under sales.
Marketing is all about the selling our product so here we are selling our vacancy to good candidates and being a consultant selling our candidates.
I hope .. this must have cleared your concept.
Regards