inboxes.

MAIL TESTER // FULL PLACEMENT

Mail Tester: See Where Your Email Lands, Not Just a Spam Score

A spam score out of 10 does not tell you where your email lands. The Inboxes mail tester sends your real email to a seed panel of live mailboxes and shows the placement board: inbox, Promotions, or spam, provider by provider, with the ranked fixes underneath.

How testing works
Placement test live

Inbox placement

67%

··%

· ·

Authentication

SPF · DKIM · DMARC

checking 130+ blacklists

Sample data. Seed results are estimates, not guarantees.

12,400+ placement tests run 6+ providers 130+ blacklists Ranked fixes

What is a mail tester?

A mail tester is a tool that checks an email before or after a campaign send: where it lands, whether its authentication passes, and what triggers spam filters. Inboxes is a mail tester built on real placement: you send one email from your own ESP to a seed list of live mailboxes at Gmail, Outlook, Yahoo, iCloud, GMX, and Zoho, and the board shows where each copy landed. Every test also reads SPF, DKIM, and DMARC results from your actual headers, checks your sending IP against 130+ blacklists, and returns a fix list ranked by impact. Seed results are directional estimates of real audiences, not guarantees, and no honest mail tester will promise you the inbox.

// what the test reads from your headers

Authentication-Results: spf=pass smtp.mailfrom=news.example.com;
  dkim=pass header.d=example.com; dmarc=fail (p=none) header.from=example.com
X-Received: from seed-gmail-07 [placement: PROMOTIONS]

Real header parsing from the seed mailboxes, the same signals the receiving filter used.

What you get

Mail tester, done properly

Placement, not a proxy score

A single spam score hides more than it shows. The board reports the actual folder your email hit at every seed mailbox: inbox, the Promotions tab, or spam.

Your real sending path

You send from your own ESP, so the test judges the exact combination the mailbox providers judge: your domain, your IP pool, your template, your headers.

Auth and blacklists in the same pass

Every test parses SPF, DKIM, and DMARC from the received headers and checks the sending IP against 130+ blacklists, so the why arrives with the where.

A fix list, not homework

Results end in ranked, concrete actions: the record to publish, the include to add, the delisting to request. Re-test after each fix and watch the board change.

How it works

From send to fix list in four steps

01

Start a test

Create a test in Inboxes and get your seed list plus a test ID for the subject or body.

02

Send from your ESP

Send your real email from your normal platform to the seed addresses. Nothing to install.

03

Read the board

Within minutes the placement grid fills in per provider, with auth results and blacklist hits alongside.

04

Work the fix list

Apply the ranked fixes in your DNS and ESP, then re-test to confirm the change landed.

The honest boundary: seed results are directional estimates and nobody can guarantee inbox placement. Inboxes finds the fixable causes, tells you exactly what to change, and monitors the result. No warmup networks, no bot opens, ever. Full detail on the methodology page.

Related deliverability tools

Run your first test in about five minutes