I'm running a Drupal 4.7.2 based website for a project. On this website, I created 3 roles of users and I approve/deny every single user that signs in.
Now, my boss asked me if it is possible that the user of a new partner's website (also in Drupal) can automatically become users of our site with their profile on the other site.
Is it possible? I want to keep this procedure safe and sound, how can I do it?