Learn about DMARC, SPF, and DKIM

One of the more frustrating Outlook.com incidents is this one: the sending IP looks technically clean, SPF and DKIM pass, the domain is not obviously broken, and yet Microsoft still throttles, junks, or blocks the mail.

That is not as contradictory as it sounds.

At Microsoft, a "clean IP" does n...

When Outlook.com starts throttling, junking, or blocking a sender, the instinct is usually to ask Microsoft for delisting immediately.

That is understandable, but it is often the wrong first move. Microsoft is fairly clear about the order of operations: follow the published policies, fix authentic...

When mail starts slowing down, landing in Junk, or getting rate-limited at Outlook.com, many teams look at SPF, DKIM, and DMARC first. That is still the right first pass, but it is often not enough. Microsoft's own sender tooling is where the investigation becomes practical.

Smart Network Data Ser...