We process about 50k messages per week and use dmarcian, but we are thinking about moving to valimail as they have insight into m365 internal only sending services. Don’t let my username fool you. I’d rather be knitting but it doesn’t pay like SA work.
We will have the sales pitch soon - but they say they have easy auth for third party services so no spoofing. We bleed third party crap these days. Everything wants to freaking spoof our domain. If I can get docusign, etc to not fail it will be great and I will gleefully move from reporting only to enforcement. Dmarcian does the reporting and all, but doesn’t really proactively help with stragglers