The Metadata tab contains 3 fields:
Generic Fieldset: Is the name of the Knowledgetree DMS field set that holds the metadata fields used by the SEAD HUB.
Email Folder: Is the optional folder name to create as subfolder when archiving emails.
Subfolder Metadata field: Declare a field from the generic field set. The value from that field will be used as a subfolder name when archiving emails.