How we estimate Accepted and Inbox
Every email test shows two numbers for Gmail, Yahoo, Outlook and Apple. Both are estimates, not promises: no provider publishes how its filter decides. Accepted comes from the rules they do publish; Inbox also learns from mail we know the answer for.
Accepted: will the provider take it at all?
From that provider's published sender rules and two facts every receiver checks: your domain's DMARC policy, and whether the sending server is on a blocklist. We start at 99% and take the lowest band that applies:
| What the message shows | Accepted |
|---|---|
| Every rule the provider publishes for this mail is met | 99% |
| A bulk-mail rule missed (marketing mail only) | 85% |
| DMARC fails and the domain asks for quarantine | 85% |
| A rule for all senders missed | 60% |
| The sending IP is on a blocklist we query | 40% |
| DMARC fails and the domain asks receivers to reject it | 5% |
These bands are our own settings, based on each provider's published rules, not measured rates. "Quarantine" means the provider files failing mail in spam; a rule for all senders is one the provider applies to every sender, not only to bulk mail.
A rule we could not check never counts as a miss: a lookup that timed out says nothing about your mail. Bulk-mail rules, such as one-click unsubscribe, count only when the message reads as marketing mail.
Inbox: inbox or spam, once accepted?
One AI read of the whole message answers whether it looks like unwanted bulk mail, spam or a scam. It sees the subject and the start of the text with addresses, links and long numbers masked, the sender headers, our own authentication results, and your domain's age and DNS. It never sees who the message was sent to.
We tuned this on emails where we knew where they really landed, then tested it on emails it had never seen. Each result shows how often it was right in that test. The Inbox figure on a result is a share of all the mail you send, so it is never above Accepted.
One rule sits on top: when DMARC fails and your domain asks receivers to quarantine or reject failing mail, Inbox is capped at 5%. That is your own policy at work. Without an AI read, there is no Inbox number at all, never a guess.
Why the four providers can differ
Only where their published rules differ: Gmail asks for an encrypted connection (TLS), Apple asks for an unsubscribe link on marketing mail, Outlook applies most rules to bulk senders only. The Inbox number is the same for all four for now, because we have no signal that is specific to one provider, and we do not invent one. Your answers to "Where did it land?" will let that change.
What no test can see
Your spam complaint rate and your sending reputation at each provider. Only the provider's own sender tools show those, and they move the result as much as anything in one message.
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