When you create an account, (the master account) you use your email address as the contact email and the user name for login to the main management interface (a.k.a. Client Area)
Since this information must be unique to each customer, you cannot change it yourself.
You will need to contact firstname.lastname@example.org for the master account email to be changed.
As an alternate solution, we recommend that you create a sub user (for yourself). That way you can access your account without an email change.
This also helps us protect your account from unauthorized changes.
If you cannot login to the client area and absolutely must change this information, then you must complete a security check by submitting and Contact Change Form.