Apple ID email

I have a 2011 Mac using Maverick 10.9.5.
When I purchased I set up Apple ID with my current email which is AT&T. I have an icloud email and would like to make that my primary email account.
The icloud email is listed as an alternate account. How do I make that the primary so my emails on my iPhone and iPad are coming for the icloud address and not the AT&T?

Jagsfish the Apple ID is used exclusively in the App Store etc. Take it you mean you used your administrator password for email?

Not sure. I am trying to to send an email with my new address at icloud. When I open mail, the old ATT address is there. How do I change that? Thank you

Do you mean that the Mail program defaults to using the AT&T account to send from? If so, try the following:

!. Open Mail preferences and click the Accounts tab (second icon from left in the toolbar)
2. Select the iCloud account and make sure enable this account is checked.
3. In the Outgoing server section check "Use only this server"