no entendi mucho tu duda, pero para ejecuta Outlook Expres
es asi
Private Declare Function ShellExecute Lib "shell32.dll" Alias "ShellExecuteA" (ByVal hwnd As Long, ByVal lpOperation As String, ByVal lpFile As String, ByVal lpParameters As String, ByVal lpDirectory As String, ByVal nShowCmd As Long) As Long
Const SW_SHOWNORMAL = 1
Private Sub Form_Load()
ShellExecute Me.hwnd, vbNullString, "mailto:shadow_enn_357 @ Hotmail.com", vbNullString, "C:\", SW_SHOWNORMAL
End Sub
es asi
Private Declare Function ShellExecute Lib "shell32.dll" Alias "ShellExecuteA" (ByVal hwnd As Long, ByVal lpOperation As String, ByVal lpFile As String, ByVal lpParameters As String, ByVal lpDirectory As String, ByVal nShowCmd As Long) As Long
Const SW_SHOWNORMAL = 1
Private Sub Form_Load()
ShellExecute Me.hwnd, vbNullString, "mailto:shadow_enn_357 @ Hotmail.com", vbNullString, "C:\", SW_SHOWNORMAL
End Sub