How can I add more users to this account. I tried to add a user and he never got an email to login

You are much right, I made a test and the email never arrives.  Unless you have the user to create a free account first and then add her email address to your main account, not the ideal, but that's the way it works.

I have opened a ticket to find out if that's the normal way or this should be enhanced.

Actually, I used a gmail address and the email arrived after 5 minutes. Please let us know the email address otherwise, try with a public one (gmail, yahoo, etc)