I'm writing this up because I've often seen the question "How do I extract email attachments at command line?". I had to figure out how to use various tools to do this recently and figured I'd share what I did.
EDIT 11-Nov-2015:
While what is written below certainly works for extracting email attachments including those sent by OSN it turns out Oracle does NOT include all fields in the email they send so we ultimately abandoned this setup for OSN and are instead...