I would suggest that it’s a phishing mail as well – one because it’s actually rather vague with no actual domain name mentioned (i.e. .co.uk, .com, etc) and two because once you’ve got your domain name, it is registered to you and cannot be utilised by someone else until it comes up for renewal.
The only other thing that I can think of is… let’s say you own http://www.daguerreotype.com, that wouldn’t stop someone buying http://www.daguerreotype.co.uk and that’s something that you may not want. For example the domain http://www.creativeimagemaker.com had been taken, but I bought http://www.creativeimagemaker.co.uk for my magazine.
David.