Hi there. Bit of a n00b to notmuch and having some problems using it
alongside gnupg to decrypt emails in Emacs.

I'm running Emacs 24.5.1 on Ubuntu 15.10 (x86_64) with notmuch v 0.20.2 and
the emacs notmuch package 20160108.432 from melpa (but have had identical
results with v 0.21 from melpa-stable).

Following the instructions on the emacstips page
<https://notmuchmail.org/emacstips/>, I'm inserting
`(notmuch-crypto-process-mime t)` into my `init.el` file -- after
successfully running `(require `notmuch)`. I get the error

Symbol's function definition is void: notmuch-crypto-process-mime

Have searched around a bit and not been able to turn up any fixes. Does
anyone have any pointers as to how I could troubleshoot and/or links to any
step-by-step tutorials for getting this setup?

Thanks in advance,

Austin