Patent attributes
An online service may receive a request by a first user to provide a notice or other communication to a second user. The request may specify an email address or other communication address in order to identify the second user. The specified email address may be different than the primary email address by which the second user is known to the online service. Upon receiving such a request, the online service emails the second user using the specified email address and asks the second user to log on to the online service. When the second user logs on, the online service adds the specified email address to the account information of the second user as a secondary email address. When a subsequent request specifies the secondary email address, the notice is sent instead to the primary email address of the second user.