[Rookie42]

It inst perfect, but it doesn't need to be unless your risk is disproportional to the market. Risk will always be there, you just need to manage it inline with your corporate risk tolerance - and implementing DMARC to P=Reject is most likely going to (very likely exceed) that approach.

Yes, some companies have elevated risk here (Banks, Payment Processors, Social Media companies) - but honestly most don't.

Btw - this is as much an acceptance as a survival strategy - nothing will ever be perfect, not without significant cost & impact elsewhere. Survival of the fittest these days is managing (and please the understanding of) risk better than others