Yes, you can edit your default email address at any time. To edit your email address:
Visit the Email Control Panel and click the "Edit User" link under your name.
On the following page, click "Change email."
In the pop-up that opens, enter the new email name. Note that your email address can include only letters, numbers, hyphens, periods, and underscores.
Note: When you change your email address, mail sent to the original address will be returned to sender (unless you have a catch-all mailbox).
When you're done, click "Save."
If you've set up POP to check your email, be sure to edit those settings to reflect your new email address.