no, all the files are physically located at mydomain.co.uk. The shopURL.com URL is hosted elsewhere (with no server available) and is therefore using a redirect to point to the physical path at mydomain.co.uk/zendirectory.

The problem is that all emails refer to HTTP_SERVER, which is messy as it doesn't contain the 'real' domain. I could go through and edit them all, but that's a pain, so I wondered if just changing the HTTP_SERVER would actually matter now that it is all installed.