A few weeks ago I've started noticing spam alike emails coming to my work email address from some small company's VP trying to push their advanced bug detecting software. First, I ignored them and kept marking it as spam. However, the person seems to be extremely persistent and just keeps emailing me follow-ups and eventually asking if he is knocking on the wrong door. I do not usually get involved with things like that but what is the proper thing to do in such situation to keep things ethical and at the same time safe for my employer?
Should I keep blocking him; should I report him to our IT department or should I actually respond by saying literally "sorry, but we are not interested"?
My concern is that I do not want to initiate any kind of communication of such sort via company's email and at the same time I understand that there is no solid reason to be rude to that person, although he DID guess or get hold of my email without my approval.