Sub vbarch()
Dim NS As Outlook.NameSpace
Set NS = GetNamespace("MAPI")
Dim MF As MAPIFolder
Dim i As Long
For Each v In NS.Session.Folders
    Set MF = v
    subFld MF, MF.Name
Next v
End Sub
 
Sub subFld(ByRef MF As MAPIFolder, txt As String)
Dim v As Variant
Dim sMF As MAPIFolder
MsgBox txt, , MF.Name
For Each v In MF.Folders
    Set sMF = v
    subFld sMF, txt & "-" & sMF.Name
Next v
End Sub