This is old news, but it bears posting because people continue to fall vicitm to it. There's a few companies well known for sending people bogus domain name registration reminder notices through the mail. The best known one is the Domain Name Registry of America, but by the time you read this, their name may have changed or a copycat sham business may be doing the same dirty deeds.
If you own a domain name for a website, you've probably already gotten a renewal notice by mail from a company called Domain Registry of America. They've got the nice colorful American flag as their logo. That's just where the deception starts.
First, it's a Canadian company. Second, they probably aren't your registrar though they use deception to fool unsuspecting people into thinking that they are their registrar. They've already been busted by the FTC and have modestly reformed their act so that they now have to disclose that they're not your registrar and that they want you to transfer your domain name to them, but they word it very cleverly that confuses most people.
Don't be fooled. The main service they offer is still conmanship. Their one year renewal price for a domain name is several times the rate of a competitive price for a domain name and twice the cost of what I consider a reasonable registration fee ($15). Most reputable registrars that charge competitive rates do not send you mail reminders via the post office because the margins are so razor thin for discount domain name registrars that they could literally waste any profit they make on postage.
If you find postal mail notices a valuable service, there are other companies that will do it without being unethical in exchange for a premium fee. Network Solutions is one company that used to send notices by postal mail, but I'm not sure if they still do.