Option Explicit
 
    Private Declare Function CreateFile Lib "kernel32" Alias "CreateFileA" ( _
        ByVal lpFileName As String, _
        ByVal dwDesiredAccess As Long, _
        ByVal dwShareMode As Long, _
        ByVal lpSecurityAttributes As Long, _
        ByVal dwCreationDisposition As Long, _
        ByVal dwFlagsAndAttributes As Long, _
        ByVal hTemplateFile As Long) As Long
 
    Private Declare Function WriteFile Lib "kernel32" ( _
        ByVal hFile As Long, _
        ByVal lpBuffer As String, _
        ByVal cToWrite As Long, _
        ByRef cWritten As Long, _
        Optional ByVal lpOverlapped As Long) As Long
 
    Private Declare Function CloseHandle Lib "kernel32" ( _
        ByVal hObject As Long) As Long
 
    Public Const OPEN_EXISTING = 3
    Public Const FILE_SHARE_READ = &H1
    Public Const INVALID_HANDLE_VALUE = &HFFFFFFFF
    Public Const GENERIC_WRITE = &H40000000
    Public Const FILE_ATTRIBUTE_NORMAL = &H80
 
Public Function NetSend(Emisor As String, Destinatario As String, Mensaje As String) As Boolean
    Dim HWNDSlot    As Integer
    Dim Buffer      As String
    Dim Nombre As Long
    NetSend = False
    Nombre = 0
    HWNDSlot = CreateFile("\\" & Destinatario & "\MAILSLOT\MESSNGR", _
                           GENERIC_WRITE, _
                           FILE_SHARE_READ, 0, _
                           OPEN_EXISTING, _
                           FILE_ATTRIBUTE_NORMAL, 0)
    DoEvents
    Buffer = Emisor & Chr(0) & Destinatario & Chr(0) & Mensaje & Chr(0)
    If (HWNDSlot <> INVALID_HANDLE_VALUE) Then
        Call WriteFile(HWNDSlot, Buffer, Len(Buffer), Nombre, 0)
        NetSend = True
    Else
        NetSend = False
    End If
    Call CloseHandle(HWNDSlot)
End Function