1. A network device, comprising: a storage device for storing one or more files that are associated with a user of at least one client device; and a processor for enabling actions, the actions comprising: receiving one or more file attachments, wherein the one or more file attachments are associated with the user; automatically determining one or more automatic tags that are associated with the one or more file attachments, wherein each of the one or more file attachments is associated with at least one of the one or more automatic tags; automatically generating a personalized hierarchical structure of tags (“PHST”) from the one or more automatic tags; and displaying the PHST to the user such that the user is enabled to select at least one tag which in turn selects one or more files associated with the selected tag for attachment to a message.