The Email Address field cannot be altered directly from your account for security reasons. This way in case someone compromises your Netz0 account, you can still be alerted and recover access.
If you need to update your account email address, just contact us by opening a support ticket. If you instead need to add other contacts to your account, you can do so with the Contacts/Sub-Account feature page.
It is important to keep your current email account up to date as this address is where you receive all communications from Netz0 regarding your account and services.