A method and apparatus for using an intermediary to manage unwanted electronic messages is provided. The intermediary generates a unique address for each pairing of a user and an e-mail resource, such as a mail list. The intermediary maintains a database that identifies which user and which e-mail resource is associated with each unique address. When the intermediary receives messages, the intermediary identifies the user and the e-mail resource based on the database. The intermediary sorts messages for each user based on groups that are associated with each e-mail resource. The intermediary filters the messages to identify messages that are unwanted by the user, such as mass unsolicited e-mail. The intermediary identifies unwanted messages by comparing the sending address for each message to a list of authorized sending addresses for the e-mail resource, and by analyzing the content of the messages, such as identifying whether the messages contain hidden images.