15. The method of claim 13 , wherein the related out-of-scope items include cross-folder items.
13. A computer-implemented method executing on at least one processing circuit, comprising: receiving user input identifying a scope for item retrieval, wherein scope comprises at least one of: a local storage location for items, or a search query for retrieving one or more items, the items comprising at least one of: electronic mail messages and electronic mail message attachments; retrieving items according to the identified scope; associating out-of-scope items related to the retrieved items with the retrieved items into an aggregate conversation header of the user interface; and presenting a group of the aggregated items in a hierarchical display within the aggregate conversation header, the hierarchical display to identify relationships between the related out-of-scope items, the relationships being operative to visually differentiate the related out-of-scope items with the retrieved items within the identified scope.