If you own or manage a domain name it is very likely that you would have at some point received a letter from, The Domain Registry of America, telling you to renew your domain. These letters are commonly sent when your domain is approaching renewal, looking very much like an invoice reminder they also tend to contain an extortionate renewal fee.
I can confirm that these letters are never legitimate and although they give the impression that they are associated with your current registrar, there sole purpose is to make money under these false pretenses.
Another letter you may also receive would simply enquire similar domains to your own, but with differing extensions (such as .cn), saying that it's vital that this is registered - at ~£80/year - before someone else registers it. If you get one of these, first think if there is any point in your business registering a .cn domain, and if there is then register it through a reputable registrar rather than one who sends misleading sales letters through the post or email.
If you ever receive a letter The Domain Registry of America, also known as the Domain Registry of Europe and Domain Registry of Canada, please take no notice and dispose of them. We will always email you in regards to your services and will never send you letters through the post. If you are ever in doubt, please contact us and we will happily clear things up for you.