You appear to have made up your own syntax for objFolder. The following should be closer

Sub MoveToFolder(newmail As Outlook.MailItem)
Dim objNS As Outlook.NameSpace
Dim objFolder As Outlook.MAPIFolder
Dim SubFolder As Outlook.MAPIFolder

    Set objNS = GetNamespace("MAPI")
    Set objFolder = objNS.GetDefaultFolder(olFolderInbox).folders("Opportunities").folders("Customers")
    For Each SubFolder In objFolder.folders
        If InStr(newmail.subject, SubFolder.Name) Then
            newmail.Move SubFolder
            Exit For
        End If
    Next
    Set objNS = Nothing
    Set objFolder = Nothing
    Set SubFolder = Nothing
End Sub