When I run this code in an Outlook module with a blank new message open, I get two insert file buttons. The first one doesn't seem to do anything, while the second one is the familiar one from the Insert menu and the Standard toolbar. Actually, if you run out a list of all the controls on the toolbar, including controls that aren't visible by default, they are both there. Very mysterious...

<code>Sub NewCtrlTest()
Dim cBar As CommandBar, cbarBtn As CommandBarButton
Set cBar = ActiveInspector.CommandBars.Add("Testing Only", , , True)
cBar.Visible = True
Set cbarBtn = cBar.Controls.Add(ID:=777)
cbarBtn.Style = msoButtonIconAndCaption
Set cbarBtn = cBar.Controls.Add(ID:=1079)
cbarBtn.Style = msoButtonIconAndCaption
Set cbarBtn = Nothing
Set cBar = Nothing
End Sub</code>

I guess perhaps the 777 button is used in a particular context that isn't obvious to me, or simply lingers for no good reason from earlier versions of Outlook (OL97: How to Use Command Bars in Outlook Solutions).