My bad,

I was looking in the site administration block rather than the course administration one. Yes the menu is there as expected, the groups are segregated and I can use the course participants menu to bulk message a group.

Are people extensively using the groups functionality to segregate disperate learners (in our case from different organisations) or are there other mechanisms that should be looked at such as having clones of the primary course for different organisations,

Thanks in advance, Fergal