The function of marking an email message is to designate it for future action. This action can include follow-up, reminder, or prioritization within an inbox. For instance, if a recipient receives a message requiring a response after further investigation, they can mark it for later attention rather than allowing it to be lost amongst newer correspondence.
The usefulness of this feature lies in improved email management and workflow efficiency. It prevents important messages from being overlooked and supports a more organized approach to inbox processing. Historically, the practice mirrors physical methods of document management, where physical flags or colored tabs were used to denote status or required actions. This digital analogue allows for a streamlined approach in a paperless environment.