“Best If Used By”: Expiration Dates for Email

We recognize the ephemerality of certain kinds of email received, and propose the use of an expiration date tag to indicate its lifetime. We hypothesize that the use of such a tag will assist personal information management (PIM) by providing users the ability to prune their email archives automatically, and take other actions as appropriate. We situate our proposal of expiration tags within the current PIM literature, focusing on the research problems they may help solve. We conclude with a discussion of how expiration tags can be set, retrieved, and acted upon by mail clients.