Private Sub btnTest_Click(ByVal sender As System.Object, ByVal e As _
   System.EventArgs) Handles btnTest.Click
        OpenFileDialog1.Filter = "xls files (*.xls)|*.xls|All files (*.*)|*.*"
        If OpenFileDialog1.ShowDialog() = DialogResult.OK Then
            Dim file As String = OpenFileDialog1.FileName
            OpenEmail("frihi@bluewin.ch", "Stundenplan", file)
        End If
    End Sub
 
    Public Function OpenEmail(ByVal EmailAddress As String, _
       Optional ByVal Subject As String = "", _
       Optional ByVal Body As String = "") _
       As Boolean
 
        Dim bAns As Boolean = True
        Dim sParams As String
        sParams = EmailAddress
 
        If LCase(Strings.Left(sParams, 7)) <> "mailto:" Then _
            sParams = "mailto:" & sParams
 
        If Subject <> "" Then sParams = sParams & _
              "?subject=" & Subject
 
        If Body <> "" Then
            sParams = sParams & IIf(Subject = "", "?", "&")
            sParams = sParams & "body=" & Body
        End If
 
        Try
            System.Diagnostics.Process.Start(sParams)
        Catch
            bAns = False
        End Try
        Return bAns
    End Function