A Folder For Each Direction
Two-way channels come with two folders, created for you. The outgoing folder is where you drop files for the partner — they can read and download, but never change or delete. The incoming folder is where the partner uploads to you — they can write, but never read back or delete. A safe drop-off one way, a write-only mailbox the other. A delivery-only or collection-only channel gets just the folder it needs.