Because Aruba now utilizes a Single Sign On solution for site logons, it is doubtful that you can tie a second email to your account. However, you do have the ability to change it. Where to do it depends on your account type (Partner, Social, Support Entitlement, etc.).
From the SSO FAQ:
Aruba Partner Center and Support portal users must re-register with business email addresses in order to change the entitled email address. Airheads Social users can change email address from Airheads Social by clicking on the “Update User Information” button on the “My Settings” page. (The link is only available after you login.) Please note that if your SSO email address entitles you to Support Portal or Partner Center access, you will lose the entitlement if your account email address is changed.