The E-Mail address is used as the primary login into your Penta account, therefore this change should be avoided due to security reasons.
You can also change the e-mail address yourself in your account. Please go to the menu "Administration" --> "Company information" --> "Legal representatives". There you can change the e-mail. The change is secured by the SMS TAN procedure.
If you absolutely require the change of the email address on file, please reach out to our customer support team.