Email Deliverability Testing and Inbox Placement

Why “delivered” is not the same as “read”

Your sending platform reports a delivery rate of 99%. Your open rate is 4%. Both numbers are correct, and together they describe a campaign that failed.

“Delivered” only means the receiving mail server accepted the message. It says nothing about where that server then put it. An email deliverability test closes that gap. It tells you the one thing your delivery rate cannot: whether a human being will ever see the email.

Placement also differs by provider. Gmail may inbox you while Outlook quietly files the same message in junk. An average hides that completely, which is why the test reports each provider separately.

How to test email deliverability

The test takes about five minutes and runs before the campaign reaches anyone real.

• Finish the campaign first. Use the real subject line, sender name, content and links. Testing a half-built draft tells you about the draft, not the send.
• Send it to the seed list. One click routes the campaign to monitored mailboxes instead of your subscribers.
• Read the placement result. Within minutes you see inbox, promotions or spam at each provider. Read them one by one rather than as a single score.
• Fix what the test found. Spam at one provider usually points to authentication or reputation with that provider. Spam everywhere usually points to content or list quality.
• Retest, then send. Re-run after each change. When placement is clean, send to your real list.

Run it before every major campaign, after any change to your sending domain or IPs, and whenever open rates drop without an obvious cause.

What a seed list is, and how the test works

A seed list is a set of real mailboxes that neuMails maintains and monitors across every major provider. Your campaign goes to those addresses, and we check where each copy landed.

It works because the mailboxes are real. Spam filters judge a message by sender reputation, authentication, content and recipient behaviour — none of which can be simulated reliably. Sending to genuine accounts at Gmail, Yahoo and Outlook produces the same filtering decision your subscribers would get.

What to do when the test finds a problem

A failed test is useful. It tells you where to look.

• Spam at one provider only. Usually authentication or reputation with that provider. Check your records with the email authentication wizard.
• Spam everywhere. Usually content or list quality. Look at link reputation, image-to-text ratio, and whether the list contains addresses that never asked for your mail.
• Promotions tab instead of inbox. Not a failure. Gmail sorts most marketing mail there, and engaged subscribers still read it.
• Placement worse than last month. Check whether bounce or complaint rates moved in email analytics before changing the campaign.

For a single message rather than a campaign, email logs show the exact response from the receiving server.