MeysamMicrosoft's enforcement just changed the game
since May 2025, Microsoft requires DMARC, SPF, and DKIM for bulk senders hitting outlook.com
Google and Yahoo started in Feb 2024
that's the three largest consumer mailbox providers now aligned on authentication requirements
if your domain sends any email — newsletters, transactional, marketing — and you're still at p=none, you're not just risking spam folder placement
