Still Using an @gmail.com Address for Business?

The Introduction

I’m attending a big networking event and a gentleman walks toward me from across the room.  He tells me his name, we shake hands and chat for a few minutes about a question he has.  I want to keep in touch and can think of another professional I would like to introduce his business to and so I ask for a card.  We exchange cards, smile, shake hands and he walks away.  I look down at the card and then I see it:  d***c****@yahoo.com.  My head drops.