Multiple email addresses in automated workflow


I have a webform which asks for the form users email address.

At the end when they submit it sends an alert to multiple people including the form users email address all at once (approx 4 emails).

Instead of 4 different people/teams getting an alert from me (owner of the box) I'm looking for the a single email with all their name included in the one To field so anyone can REPLY ALL and it gets the rest of the team avoiding me being the middle guy keeping everyone in the loop.

I'm sure there is a way. I tried joining columns of different Contact List but can't get it work (tried , and ; between email addresses) into a Contact List (allow multiple contacts) but that didn't work.

Help Please