How should you report inboxing health internally?

Most teams track inbox placement the wrong way. They look at open rates from their ESP and call it a day. But open rates only tell you what happened after an email landed in the inbox. They say nothing about how many emails never made it there at all.

If you want to report inbox health in a way that actually means something, you need to track three core numbers: inbox rate, spam rate, and missing rate. Inbox rate is the percentage of emails that landed in the inbox. Spam rate is the percentage that got filtered to the spam or junk folder. Missing rate is the percentage that simply vanished, no bounce, no delivery, just gone. These three together give you the full picture.

For most teams, the simplest format is a weekly or bi-weekly summary. Track those three numbers per major mailbox provider. That means separate rows (or cards) for Gmail, Outlook, and Yahoo Mail at minimum. Providers behave differently, and a problem showing up at Gmail but not Outlook usually points to something specific about how Google sees your domain reputation.

Pair that with a trend line, not just the current snapshot. A 78% inbox rate sounds acceptable until you see it was 92% six weeks ago. Direction matters as much as the number itself.

What to flag as a problem:

• Inbox rate dropping more than 5 percentage points in two weeks
• Spam rate climbing above 3-5% at any major provider
• Missing rate above 1-2% (this often signals a blocklisting or authentication failure)
• A dip at one provider that doesn't show up at others (provider-specific reputation issue)

You can also pull reputation signals directly from the source. Google Postmaster Tools gives you Gmail-specific domain reputation and spam rate data. SNDS (Smart Network Data Services) is Microsoft's equivalent for Outlook traffic. Both are free. If you're not checking them at least once a week, you're flying blind on two of the biggest mailbox providers in the world.

When it comes to who's reading the report, you'll want two versions of the same data.

For executives or non-technical stakeholders: one headline number per send (inbox rate), a red or green status indicator, and one plain-language sentence about any change. That's it. Most leaders don't need granular provider breakdowns. They need to know whether the program is healthy and whether something needs attention.

For operations teams or whoever manages deliverability day-to-day: the full breakdown by provider, trend lines over 30-90 days, reputation scores from Postmaster and SNDS, and a short list of action items. This group needs enough detail to diagnose problems, not just spot them.

But one last thing worth adding to any internal report: an engagement correlation section. Show how inbox rate tracks alongside open rate and click rate over time. When inbox rate drops and opens follow, that's the business impact made visible. It's the clearest way to explain to a skeptical stakeholder why inbox placement metrics aren't just a technical concern. They're a revenue concern.

If you're not sure where to start building this kind of view, our SOS hotline is free and we're happy to walk through what matters most for your specific setup.