How to interpret mixed results (inbox + spam + missing)?

You ran a test send and the results are all over the place. Some emails landed in the inbox, some hit spam, and a few seem to have vanished entirely. That's actually three separate problems in one report, and they each need a different response.

Here's how to break it down.

Emails landing in the inbox are your control group. Note which providers accepted you (for example, Gmail inbox but Outlook spam) and use those clean results as a baseline. If Gmail is happy with you and Outlook isn't, that's a provider-specific reputation issue, not a content problem.

Emails landing in spam mean the message arrived but got filtered. That's diagnosable. Check your SPF, DKIM, and DMARC alignment first. Then look at the specific providers where spam placement happened. Different filters flag different things. Outlook's filters care a lot about IP reputation. Gmail cares more about engagement history and content signals. Knowing which provider flagged you tells you where to look next.

Missing emails are the most urgent. A spam placement means the message arrived. Missing means it didn't. That gap usually points to one of three things: a hard bounce (the address doesn't exist), a silent block at the gateway level, or a temporary delivery failure that the test tool stopped retrying. Pull your sending logs and look for bounce codes or error responses for those addresses. If you see a 550 or 421 error, that's your clue. If there's no error at all, the sending IP may be blocked upstream before the message even reaches the inbox provider.

A useful way to work through mixed results is to sort them by provider first, then by outcome. Something like this:

• Gmail: inbox across all test seeds? Your content and authentication are probably fine for Google.
• Outlook: spam on half, missing on the rest? You may have an IP reputation issue with Microsoft's filters, or your sending IP is on a blocklist that Microsoft references.
• Yahoo Mail: inbox for some, spam for others? Check your DMARC policy and whether your domain is on any domain-level blocklists.

Once you've sorted by provider, look for patterns. Is the spam placement happening across all providers or just one? Is the missing mail clustering around a specific domain? If it's one provider, it's a reputation problem with that provider. If it's everywhere, it's an authentication or infrastructure issue. If it's missing across multiple providers at the same IP range, check your sending IP against blocklists right now.

And you can run a quick blocklist check with our free Blocklist Checker to see if your sending domain or IP is flagged anywhere. If you're staring at logs and not sure what you're seeing, our SOS hotline is free and we actually help (no pitch, no upsell).

One last thing: mixed results are actually more useful than all-spam results. They tell you that something is working somewhere. Your job is to find what's working, figure out why it works, and apply that logic to the placements that aren't.