Outlook is a bit fussy to program from other applications however see the comments in line

Private Sub btnMail2_Click()
Dim myMail As Object
Dim myOutlApp As Object
Dim olInsp As Object
Dim wdDoc As Object
Dim oRng As Object
'Use the function from Ben Clothier - http://www.rondebruin.nl/win/s1/outlook/openclose.htm
'To open or create the Outlook application or the process will not work as you require
Set myOutlApp = OutlookApp() 'calls Ben Clothier's code
    Set myMail = myOutlApp.CreateItem(0) 'Create a new mail item
    With myMail
        Set olInsp = .GetInspector
        Set wdDoc = olInsp.WordEditor 'get the Word document inspector to edit the message body
        Set oRng = wdDoc.Range ' Set a range to the document body
        .To = Me!EMail
        .Subject = "Betreff"
        oRng.Collapse 1 'Collapse the range to its start i.e the message start
        '(the only other thing in the message at this point should be the default signature'
        'Add text from code
        'oRng.Text = "Some message text"
        'oRng.Collapse 0 'collapse the range to its end
        oRng.Select 'type here as required
        .Display
    End With

    Set myMail = Nothing
    Set myOutlApp = Nothing
    Set olInsp = Nothing
    Set wdDoc = Nothing
    Set oRng = Nothing
End Sub