Straight from the markteting machine:
Thought that you would be interested in the news about Return Path's receipt of a patent for its Email Change of Address (ECOA) service. Launched in 2000, Return Path's ECOA service provides a fully permission-based way for businesses to find customers' new e-mail addresses and allows consumers to search for friends' and families' new e-mail addresses for free.
To date, it has been used by more than 400 companies and more than 31 million consumers have registered with the service. On average, 15,000 people register daily with Return Path's ECOA service. The patent awarded to Return Path from The U.S. Patent and Trademark Office, number 7,080,122, applies to both the system and process for updating electronic messaging accounts.