Ok I have some problems and questions

[joximu]

ah, ok.

So, do the following:

- make sure, that server.strawberrymilkshakes.co.uk resolves to the ip of your server
- best would be if the PTR Entry (reverse lookup) of the server ip resolves back to server.strawberrymilkshakes.co.uk

- change /etc/hostname (to "server" or maybe the full name)
- change /etc/hosts

- change SERVER_HOSTNAME in /etc/ispcp.conf
- change /etc/postfix/main.cf
- change /etc/proftpd/proftpd.conf

- maybe also /etc/mailname

I think this should do it - now a reboot of the server would be nice (to reflect the new hostname). And then you should be able to add strawberrymilkshakes.co.uk as a customer domain...