Occasionally people send patches produced by the Automatic Upgrade Helper and forget to recommit and change the author i.e. "Upgrade Helper <uh@not.set>" (or "Upgrade Helper <auh@auh.yoctoproject.org>"). We don't want these commits going in so we should add a check for them - I would suggest detecting these solely by email address, and also disallow .*@example.com as well.
Proposed test is being tested [1] http://git.yoctoproject.org/cgit/cgit.cgi/patchtest-oe/tree/tests/test_mbox_author.py?h=metadata-checks