Hey Thrane,
No, that is not the way it is supposed to work.

In the backend of the extension you have the option to import your users to a particular list.

If users are registering on your site, then there is an option to also subscribe those users to the list (if they decide to). But if users are just entering their e-mail to be on your list, then we don't create accounts for them on your site.

Regards,
Daniel

I see... thanks for your reply :-)
I've noticed that if a user changes his e-mail in CB, then he has to subscribe again with the CMC plugin in CB and the old e-mail remains in MailChimp?
Hope you get what I mean here :-)