Kouio was exactly what I was looking for after Google Reader shut down. It kept enough of my favourite features such as j/k vi-style movements, starring and organisation whilst adding its own. I've not run in to any hiccups, despite the beta label.
Thanks for the list of uses I hadn't considered -- I tend to lose track of mailing lists.
I'd recommend _We, The Watched_ by Adam Bender[0]. It's available in ebook or print and the author has similarly licensed it under Creative Commons (NoDerivs as opposed to ShareAlike however).
Django's Email API is already pretty solid, see the EmailMessage[0] class. Attachments and multiple MIME types are handled for sending text & html versions of the email body.
However, given that Django is just Python there's nothing precluding you from using the library as a drop-in replacement.
Thanks for the list of uses I hadn't considered -- I tend to lose track of mailing lists.