The Most Obnoxious Irani Man...

This is what you need to say to him instead of online. He knows you wont say boo to a ghost, so he is making the most of it. You need to stand up for yourself and speak your mind. Speak to other colleagues about it and get their support /adivice…and just ignore his extra hellos and interruptions, pointedly. He’ll get the message sooner or later.

and if he isnt following the policy then, you need to speak to him once, then speak to you manager.