Trademark owners are often targeted by companies with official looking letters purporting to be from an official government agency.  These companies usually have the word “trademark” in the name, e.g., “Patent & Trademark Bureau” or the like, and their purpose is to extract an exorbitant amount of money from you.  The only official agency in the United States that registers trademarks is the U.S. Patent & Trademark Office (“USPTO”) and the USPTO will never send you a letter asking for money or soliciting a service.  Other companies will try to sell you services that are completely worthless.  Do not fall prey to these companies.  Call your attorney or the USPTO directly if you are unsure what to do if you receive one of these letters concerning your trademark, or trademarks in general.