I am unable to create a “Group” in People app

I found my contacts and  added new contacts in my "People" app, but I could not create a "Group". When I tried to send each new contact an email, their names did not appear on the drop list. I restarted my computer to see if that would transfer the new contacts into my email account...it did not. So, how do I transfer new contacts in "People" onto my email accounts? Thank you!

Original title: Email Contacts & Grouping