Sry, that I come back to this, this late.
I'll try it without Cloudflare and will come back to this thread after that.

Hi KeyHelp Community, I recently installed the KeyHelp Panel and set it up. I tested several Lookups at https://mxtoolbox.com The DMARC Lookup shows this warning: "External Domains in your DMARC are not giving permission for your reports to be sent to them." And the Supertool prints out this warning ...