Public Structure Mail
       Dim iId As Short
       Dim iInfo As Short
       Dim iCommand As Short
       Dim iDataSize As Short
       Dim iFrameCount As Short
       Dim iFrameNo As Short
       Dim iOffsetHi As Short
       Dim iOffsetLo As Short
 
        <MarshalAs(UnmanagedType.ByValArray, SizeConst:=255)> Dim abData() As Byte
 
        Public Sub Initialize()
            ReDim abData(255)
        End Sub
    End Structure

Public Declare Auto Function ReceiveMail Lib "ABS.dll" Alias "ReceiveMail" ( _
  ByVal pxPath As Integer, <MarshalAs(UnmanagedType.Struct)> ByRef psMail As _
  AriadneMail, ByVal iTimeout As Short) As Integer