First of all I would convert the BMP to a JPG using the below API (attached) so the file size is significantly reduced.
Second there are no login details in your app?
VB Code:
'This converts the bmp to jpg
Public Declare Function BmpToJpeg Lib "Bmp2Jpeg.dll" _
(ByVal bmpFileName As String, ByVal JpegFilename As String, ByVal CompressQuality As Integer) As Integer