Content is provided to electronic mail, commonly known as e-mail, over a network, such as the Internet. This content is provided in accordance with keywords, typically organized in a hierarchy. The presently highest ranked keyword, that is active, is passed to various content servers, along the network, in response to a request, returned from the e-mail client of a recipient user. The keywords are managed, such that after a certain number of responses from the recipients of the electronic mails, to content in each e-mail generated from a particular keyword, use of that particular keyword is terminated, as the keyword is inactivated. Content is then delivered in accordance with another keyword, typically the next highest ranked keyword.