Email profile preference change problems....

I am having a problem trying to put in a new email address that i will need to use because my comcast account is getting closed (Yes comcast doesnt have free email we just found out).  how do i go about making my email default to another? i tried changing it in the profile, but every time I hit the save button for a new email address it clears it and puts my old email address ....why is this happening?

You will have to go to your account not your profile and change it. Click on your name in the top right corner and select account. Top left corner  on the account page has the following lines to edit: first name, last name, email, display name. Choose what you wish to change then click the save button.