What replaced pct= in DMARC?

If you have run DMARC for a while, you have almost certainly seen pct= in a record, or been told to ramp it up slowly: pct=10, then 25, then 50, then 100. The DMARCbis update removes pct= from the spec. Here is what to do instead.

First, what pct= was for. It told receiving servers to apply your policy to only a slice of failing mail. p=reject; pct=25 meant "reject a quarter of the failures, deliver the rest as if nothing was wrong." The idea was a soft landing while you moved toward full enforcement.

Why it is going away. In the real world, pct= made a mess. Receivers applied the percentage unevenly, your reports got harder to read, and you ended up with a policy that was neither monitoring nor enforcing. Most experienced operators quietly stopped using it years ago. The update just makes that official.

What replaces it. Two things, and neither is a percentage:

• For a gradual rollout, use clean report data, not a dial. Sit at p=none long enough to watch every one of your legitimate senders pass DMARC in your rua reports. Then move to p=quarantine. Then to p=reject. Each step at full strength, moved only when the data says you are ready. This is the approach that actually worked all along.
• For signalling "I am still testing," use the t=y flag. DMARCbis keeps a testing flag that tells receivers you are in trial mode, without the random-percentage guesswork pct= created.

What to do right now. If your record still has pct=, it is not broken. Receivers honour it until the update fully lands. But stop treating it as your rollout strategy. Move on clean reports instead, and drop pct= next time you edit the record.

Our free DMARC generator can build a clean record for you, and if you want a second pair of eyes on your rua data before you turn up enforcement, the SOS hotline is free.