1. A method for customizing the subject heading of subscription email comprising: receiving an email message automatically generated as part of an email subscription, said email message having an original subject heading; querying a transformation data store to determine a conversion template associated with the email subscription; and constructing a replacement subject heading based upon construction rules specified by the determined conversion template, wherein the replacement subject heading comprises textual content extracted from at least one of a body and the original subject heading of the received email message, wherein a subject heading that is to appear within an email application that presents the received email message to a user is the constructed replacement subject heading.