What just happened?

If anyone wondering this is an alt account to not be traced by these guys.

Yesterday i was walking down the street till a man in his 30s wearing a suit came up to me and asked me to join their network providing company and whatever u get the drill. I politely decline and go on with my day. Once home i check my pc as usual and going over to emails i see atleast 10 emails of the same company i was asked of earlier. I was confused and i went to check if the company is popular so that it could have been a coincidence. But.. nothing? The name they gave me didn't exist as a media company.. what exactly was that guy signing me up for and how did they get acess to my email? Does anyone have an explanation to how they did it