Email addresses, like telephone numbers, are opaque identifiers. They're often hard to remember, and, worse still, they change from time to time. Semantic email addressing (SEA) lets users send email to a semantically specified group of recipients. It provides all of the functionality of static email mailing lists, but because users can maintain their own profiles, they don't need to subscribe, unsubscribe, or change email addresses. Because of its targeted nature, SEA could help combat unintentional spam and preserve the privacy of email addresses and even individual identities.