Many thanks for your reply, Stefan.
The only applications in use are the calendaring and contacts but there are other applications present.
I was just reading about the egw-epl-groups package and although I have a note of the ‘SubmitID’ I can’t say I have ever noticed the user/pass and it looks like I’ll need to wait a few days until I can see it again:
Your last submission was less then 6 days ago!
Once I can grab that I’ll give it a whirl.