@outl..., ... I'd guess Microsoft (e.g. free Outlook mail), so if we should use your own word, the stupid part might be on Microsoft's end, e.g. that they are refusing the deliveries, which they are very well known to do from time to time.Activity Log" @ https://dash.cloudflare.com/?to=/:account/:zone/email/routing/overview ?
Activity Log" , it means that no messages have been attempted to be delivered to the Cloudflare Email Routing service, and in that case, you will need to research this through the sender, so they can eventually consult their mail service for further assistance.


Routing Status show Enabled?



@outl...Activity LogActivity LogRouting Status