Well BLAT DLL it's a good choice, and it's free.
Take a look at Craigs Boyd weblog and search for BLAT on it for details.
Luis
>What is the best email substitute for Outlook? It would be cool to have something that can be distributed with an application, operates independently of the end user's default email client, doesn’t cost much, and runs on XP and Vista without annoying security warnings.
I never forget a face, but in your case I will make an exception :-)