If not all your MDaemon users need MDaemon Connector functionality then you can purchase a licence key which is smaller than the MDaemon licence key you already have.
Possible issues to note:
MDaemon Connector support in these scenario’s will stop once the MDaemon Connector licence size has been reached and you will not be able to enable MDaemon Connector support for any additional accounts until you either upgrade your MDaemon Connector licence size or remove MDaemon Connector support for existing users.