Tricks of the Web dev trade

Interesting approach... However, ADO supports the binary read/write functionality you seek. This is a definite bonus when your web site's host will not install your custom DLL's.

"Or, you're sending an HTML-formatted e-mail"

Which is, of course, EVIL...

"and you want to provide a 'read receipt' for that e-mail"

Which is, again, EVIL...

Use your powers for GOOD! Eschew HTML mail! Eschew spyware!

Why use a DLL? Here is a simple function I found somewhere that works fantastic for downloading files. Changing the content-type should work like the DLL. ~Jamie

function DownloadFile(strFilePath)
Dim varSplit, strFileName, objStream
varSplit=split(strFilePath, "\")
If ubound(varSplit) > -1 then
strFileName = varSplit(ubound(varSplit))
response.contenttype = "application/octet-stream"
response.addheader "content-disposition","attachment; filename=" & strFileName
response.cachecontrol = "public"
set objstream = createobject("adodb.stream")
objstream.open
objstream.type = 1
objstream.loadfromfile strFilePath
response.binarywrite objstream.read
objstream.close
set objstream = nothing
end if
end function

I managed to make this fail almost straight away simply by using a 90K image.
One modification for use is to change the line

Dim i As Integer
to
Dim i As Long

just before the 'While -- Wend' loop.

I like the idea of using ADO.
Also FSO should be worth a look into.