Just ran into a problem due to the most recent org-plus-contrib (org-plus-contrib-20170210) including org-mime.el.
This file is no longer in the contrib directory of the repo and according to the commit log
commit eb87e9b8fed78f02e3d546874cab9e471846a48e
Date: Sun Jan 29 18:47:37 2017 +0100
Delete contrib/lisp/org-mime.el
So I suspect the fact it is in the elpa package is an error.
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