I'll send the email over in a few minutes. I suspect they think I'm talking about something completely different...
Thanks for the info. I own and run the dedicated server so I suspect enabling HTTP loopback connections won't cause an issue as I will be in control of all the sites on there.
I've read an article recently on this and they mentioned (particularly on Multisites) that to enable the loopback you can add the site URL to the hosts file. I did this and it seemed to work and I managed to get the sites upgraded successfully. Is this how it should be enabled or is it better to do it via the firewall?