sending uploaded images as mail attachments

I'm working on a script that allows the user to upload several images, then base64 encodes them and attaches them to an email to me. I'm having trouble getting the images readable on the other end. I've managed to get all the MIME types and message parts straight enough to be recognized as separate parts and as files of the proper types (though mostly by trial and error, and it's not quite working 100% yet), but the images aren't readable. Can anyone help? Is there an example somewhere? I'm guessing I'm just not formatting the email or inserting the encoded images quite right. Thanks. --Dave