I use Outlook 2013 to send and receive emails from my Windows computer and whenever I check the sent items on my iPhone using the native Mail app, it defaults to Times New Roman fonts. Even when I sometimes send emails to myself from my computer and open that message on my iPhone, the message body still has the fonts displayed in Times New Roman. So whatever messages I send and receive on my computer will also show up on my iPhone Mail app as well. However, when I get emails from external people most of the time it is shown as the normal Arial font. Thanks!