3.1.4.2 Opening a Search Folder
If the search folder (2) is not active, the client MUST create the folder in the Finder folder of the store, as specified in section 3.1.4.1.
If the current date/time is later than the value of the PidTagSearchFolderExpiration property (section 2.2.1.2.5), the client SHOULD re-create the search criteria and update the search folder definition message and the search folder container.
After the Folder object is updated, or if the search folder (2) was active already, the client can open the search folder (2) as specified in [MS-OXCFOLD] section 3.1.4.1. When the search folder (2) is opened, the client SHOULD set the value of the PidTagSearchFolderLastUsed property (section 2.2.1.2.4) to the current time.