True. We send thousands of emails a week and all of a sudden a large portion weren't even delivered. Turns out it's all DMARC and once those policies were fixed

True. We send thousands of emails a week and all of a sudden a large portion weren't even delivered. Turns out it's all DMARC and once those policies were fixed (assigned at all) the delivery denials ended. This helped us: https://dmarc.postmarkapp.com https://dmarc.postmarkapp.com