Ich habe unter "Kontakt E-Mail-Adresse" eine neue E-Mail-Adresse eingetragen, aber sie funktioniert nicht!?

The field "Contact e-mail address" can only be used to specify the e-mail address via which the LRZ can contact the user if necessary, but not to create a new e-mail address for an account.

In this regard, please also note the entries What is the meaning of the field "Contact e-mail address?" and How to edit the email address(es) of an account?