If you are wondering why Outlook 2010 and 2013 email clients will not render your font-family tag correctly, you are not the only one.
This is a known issue. So despite your fallback fonts being declared these older Outlook clients will use Times New Roman instead. You can always use the code below in the head to get around certain problems of old email clients. You probably won’t be able to get it to display nice Google fonts but at least you won’t be stuck with Times.