Option Explicit
 
Private Type MapiRecip
    Reserved As Long
    RecipClass As Long
    Name As String
    Address As String
    EIDSize As Long
    EntryID As String
End Type
 
Private Type MapiFile
    Reserved As Long
    Flags As Long
    Position As Long
    PathName As String
    FileName As String
    FileType As String
End Type
 
 
Private Type MAPIMessage
    Reserved As Long
    Subject As String
    NoteText As String
    MessageType As String
    DateReceived As String
    ConversationID As String
    Flags As Long
    RecipCount As Long
    FileCount As Long
End Type
 
Private Declare Function MapiSendMail Lib "MAPI32.DLL" Alias "BMAPISendMail" ( _
  ByVal Session&, ByVal UIParam&, Message As MAPIMessage, Recipient() As _
  MapiRecip, File() As MapiFile, ByVal Flags&, ByVal Reserved&) As Long
 
Private Const MAPI_DIALOG = &H8
Private Const MAPI_LOGON_UI = &H1
Private Const MAPI_NEW_SESSION = &H2
 
 
Private Sub Command1_Click()
Dim mmessage As MAPIMessage
 
Dim Recipient() As MapiRecip, File() As MapiFile
  With mmessage
    .Subject = Text1.Text
    .NoteText = Text2.Text
    .MessageType = ""
    .DateReceived = ""
    .ConversationID = ""
    .Flags = 0
    .RecipCount = 0
    .FileCount = 0
  End With
 
  If MapiSendMail(0, 0, mmessage, Recipient, File, MAPI_DIALOG Or MAPI_LOGON_UI _
    Or MAPI_NEW_SESSION, 0) <> 0 Then MsgBox ("Fehler oder Nutzerabbruch")
 
End Sub