You can already mail more than one person at a time. Just open a blank mail and type in each users name then add a ; So it would look like this. Ugly; dconstroversial; lucyy It also has an autofillin when you do that.
Also you can go to 'Quick Links' 'Open Contacts Popup' to mail people from there as well. Just add a checkmark next to each person and then click PM user and write the PM. It will add each person by checking their name.