Well, Deleted Items holds trash, if your users keep items there that should
be retained they need some education in how to use Outlook.
Copying items to a PST file will change various properties on the items,
you'll have to accept that. It will also make backup more difficult since
each machine would need to be backed up as PST files are not supported for
storage on network shares or devices.
The basic idea would be to use the AddStore() method to add or create a new
PST file. Then you'd find the Inbox folder for both stores (creating it as
needed) and get each item in the folder and copy it to the new store. When
finished you can remove the store (PST file), although it will remain locked
by Outlook until Outlook is closed.
The code for Inbox would look something like this:
Sub BackupInbox()
Dim oBackup As Outlook.MAPIFolder
Dim oInbox As Outlook.MAPIFolder
Dim oBackInbox As Outlook.MAPIFolder
Dim oNS As Outlook.NameSpace
Dim colInboxItems As Outlook.Items
Dim colBackupInboxItems As Outlook.Items
Dim obj As Object 'Inbox items can be various types
Dim oCopy As Object
Set oNS = Application.GetNameSpace("MAPI")
Set oInbox = oNS.GetDefaultFolder(olFolderInbox)
Set oBackup = oNS.AddStore("C:\Backup.PST") 'whatever path
Set oBackInbox = Nothing
Set oBackInbox = oBackup.Folders("Inbox")
If oBackInbox Is Nothing Then
Set oBackInbox = oBackup.Folders.Add("Inbox", olFolderInbox)
End If
Set colInboxItems = oInbox.Items
Set colBackupInboxItems = oBackInbox.Items
For Each obj In colInboxItems
' get the item type here and make the new item the same as the old
one.
' needs a long series of if then tests not shown here
' example shows just a mail item
Set oCopy = colBackupInboxItems.Add(olNoteItem)
Next
End Sub
That doesn't have error handling or releasing objects, but it shows the type
of code needed for what you want.