Developer credits
Git commits in Moodle 3.6.5 by Dan Marsden
commit b48c1715dfd6b776a495f43ff1fc5858981a2d01 Author: Dan Marsden <dan@danmarsden.com> Date: Fri, 14 Jun 2019 10:02:13 +0800 Tag: v3.6.5 MDL-60347 core: debugsmtp should be a developer only setting.