For now griddler initialized in application_controller, which mean if email arrived before any helpy action trigged, griddler will use default config for everything, usually result a 500 response.
App started => access helpy (intialize griddler) => send email to email processor => ok
App started => send email to email processor => error
Here is the fix:
lixiljp@a9ad3af#diff-060d21e42b536250ae3fa8cab5ba0ab2a4d1f3cd88c6472f497887b9616356aa