This is a readable version of the procedure which sometimes showing error
"Client process could not be completed".

Meanwhile I have a better version of the add-in using Redemption's
GetSharedDefaultFolder-method. Nevertheless I'd like to know if my former
looping the folders in AddinInstance event is bad design? Maybe not all
Exchange folders are ready at this moment?
In this procedure I try to get the StoreIDs and EntryIDs of the user's
Sent-Item-folders (own plus delegate mailboxes).
The error occurs when trying to get the EntryID of an Exchange folder
(probably a Calendar). I do have sufficient rights and the error still
happens with some users only, not always and with all users.

Thanks for your advice!

 Regards,
  Jochen

-----------
Private Type UserSentFolder
   UserName As String
   FolderID As String
   StoreID  As String
End Type

Private Sub AddinInstance_OnConnection(ByVal Application As Object, _
   ByVal ConnectMode As AddInDesignerObjects.ext_ConnectMode, _
   ByVal AddInInst As Object, custom() As Variant)

   Dim oOLNameSpace      As Outlook.NameSpace
   Dim oStores           As Outlook.Folders
   Dim oFolder           As Outlook.MAPIFolder
   Dim oSubFolder        As Outlook.MAPIFolder
   Dim j                 As Long
   Dim sTempUserName     As String
   Dim sTempFolderName   As String

   
   Set oOLNameSpace = Application.GetNamespace("MAPI")
   Set oStores = oOLNameSpace.Folders

   For Each oFolder In oStores
       sTempUserName = oFolder.Name
           sTempUserName = Mid$(sTempUserName, 12) 'Text behind "Mailbox - "
                                                   '(in German "Postfach - ")
           For Each oSubFolder In oFolder.Folders
               sTempFolderName = oSubFolder.Name
               If (sTempFolderName = "Gesendete Elemente") Or _
                  (sTempFolderName = "Gesendete Objekte") Then
                   With m_udtUserSentFolders(j)
                       .UserName = sTempUserName
                       .FolderID = oSubFolder.EntryID '!!!Error occurs here
                       .StoreID = oSubFolder.StoreID
                   End With
                   j = j + 1
               End If
           Next oSubFolder
   Next oFolder

End Sub