alt Hacker News> Nobody announced it
They did: https://techcommunity.microsoft.com/blog/microsoftdefenderfo...
And it appears to be further documented here:
https://learn.microsoft.com/en-us/defender-office-365/anti-p...
https://learn.microsoft.com/en-us/defender-office-365/email-...
And other sites were reporting about it for at least a year and a half:
https://powerdmarc.com/dmarc-outlook-email-authentication/ (see #4)
Replies
hedgehog • yesterday at 8:18 PM
That says for "high volume senders" but they now apply the rules regardless of volume.
➕ show 2 replies
> For domains sending over 5,000 emails per day
That's an old announcement about a different change. As far as I can tell this one is completely out of the blue. I'm shocked by the number of people in this thread advocating for spontaneous changes without any warning.