disable excel automatic hyperlinks?

I am working with a large Excel file that I have inherited, and when I type in an email address it automatically underlines the text and creates a hyperlink. This is extremely annoying, since whenever I want to edit an address, clicking that cell automatically opens a window for sending a new message in Mail. I have figured out how to disable the link for an individual address/cell, but not how to disable this auto function for typing in new cells. Any suggestions? I would like to be able to turn this function off for this document and also as the default for new documents I create.