1. A non-transitory computer-readable medium having computer instructions stored thereon that are capable of causing operations comprising: receiving, from a user, a request for an email address managed by an on-demand database service; associating a user alias with the user; generating the email address for the user, wherein the email address includes an encrypted sequence of characters that identify the user alias and that identify an organization of the user, and wherein the email address includes a top level email domain representing a domain of a provider of the on-demand database service; providing, to the user, an indication of the email address; receiving, from the user, a first set of information specifying one or more security criteria to be applied, on behalf of the user, to messages sent to the email address; and receiving, from the user, a second set of information specifying one or more rules to be used to process the messages sent to the email address in response to the messages meeting the one or more security criteria.