1. A system, comprising: a network interface configured to: receive an electronic mail; and receive data from an email classification database; and a processor communicatively coupled to the network interface and configured to: determine that the received electronic mail comprises a classification tag comprising classification information appended to a case number, wherein: the classification information comprises a classification type identifying the email classification database associated with the classification tag; and the case number references additional classification information stored in the email classification database, wherein the case number comprises: a classifier identifying a user that classified the electronic mail, and a timestamp identifying when the electronic mail was classified; and parse the classification tag to extract at least a portion of the classification information in response to the determination; the network interface further configured to receive a change in the classification information; and the processor further configured to: create a new classification tag comprising the changed classification information and the case number; append the new classification tag to the received electronic mail to generate a tagged received electronic email; create an outbound electronic mail associated with the received electronic mail; and append the new classification tag to the outbound electronic mail.