WQA: Is this possible to do?
If you're using the list builder then there's no option to send that email with an attachment. You may want to consider uploading the document to your server and sending a link to the file instead of attaching it directly to the email. There's a good reason to do this since bulk emails from unknown senders have a high probability of being spam. Emailing a link has a better chance to make it through any filters.
You can attach documents to emails in Method but only if you're sending the email using the action Send Email.
~C