The simple reason why I was unable to email people out was because we couldn't access the server. Which also meant I couldn't access the forum software, where member accounts are held. I got an email out as soon as I could.
The server was in the UK and we will name & shame the company concerned but I have been advised against this at this stage. Regarding data recovery, I can't comment on that either at this stage, it is a variable at this time.
Thanks.