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 message file attachments, wherein the one or more message file attachments are associated with the user; automatically determining one or more automatic tags that are associated with the one or more message file attachments, wherein each of the one or more message 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; receiving, from the user, one or more custom tags for at least one of the one or more message file attachments; associating the at least one of the one or more message file attachments with the one or more custom tags; automatically generating at least one custom generated tag using the one or more custom tags; automatically modifying the PHST to include the at least one custom generated tag within the hierarchy; and displaying the PHST which separately indicates the one or more automatic tags and the at least one custom generated tag 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.
2. The network device of claim 1 , wherein the PHST includes at least a first level of tags and a second level of tags.