I would like to know if cloudflare can be used as an incoming mx server. I have a Synology mail server on a dynamic IP with DDNS configured with DKIM SPF and DMARC, I have an extremely low mail volume, and I have the problem that some senders cannot send me mail at all. I would like to know if I can configure cloudflare as an MX to perform incoming forwarding
That would be Cloudflare’s Email Routing service. Cloudflare Email Routing.
I’ll also recommend enabling Cloudflare’s DMARC Management to let Cloudflare receive and process your DMARC reports.
But note that email forwarding – irrespective of provider – is inherently unreliable, and today’s authentication requirements make it even more tricky. And Cloudflare Email Routing is a service that’s used by (possibly) millions with ZERO vetting (hello spammers!). Considering all these, if sending and receding emails is critical to you, then I’ll suggest using a full-service professional email solution – instead of stringing things together yourself.
Good luck!