Know if your email lands in the inbox. Or spam.

See where your emails land across real personal and business accounts. Schedule regular checks, run a manual test or use the API to track inbox placement and spam scores.

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Email illustration with Outlook, Gmail and Yahoo logos and inbox, Promotions and spam folders

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How inbox placement testing works

MailSlurp supplies the test addresses. Your sending service delivers the message. See where each copy lands before sending to your customers.

Gmail and Outlook provider accounts with test email envelopes

Get your test addresses

Create a test to get a fresh list of real provider inboxes and a unique tracking marker. Available coverage depends on your plan; review the accounts included in this run.

Send your actual email

Send through your usual email platform and domain. Include the exact test marker in the subject or body, and send the same campaign to every supplied address.

Example of an Outlook message placed in spam

Review each provider

Compare inbox, Promotions and spam outcomes. Pending and not-received results stay separate, so you can distinguish confirmed placement from a message that has not been observed.

Watch a real placement test.

Follow a test from its seed list to the provider report. See how MailSlurp connects the email you sent with inbox and spam outcomes, then keeps the findings ready for review.

Follow the walkthrough

Watch the MailSlurp inbox placement walkthrough on YouTube

See where every provider puts your email.

Gmail may put a campaign in Promotions while Yahoo sends it to spam. See each account's result, then inspect content and sender-domain findings to decide what to fix before your next send.

Test your email

Gmail, Outlook, Yahoo, Proton Mail and iCloud provider logos

Illustrative spam scores improving across repeated tests

Track spam scores over time

Compare spam scores across repeat tests and spot changes after a new template, sender or ESP. Use the test history to see whether your fixes reduced spam risk.

Domain health illustration showing SPF, DKIM, DMARC and spam blocklist checks

Analyze domain health

Check SPF, DKIM, DMARC and spam blocklists alongside inbox placement. Spot authentication problems and blocklist findings before your next campaign.

Connect your ESP directly

Connect your sending service and schedule regular placement tests. Send through your own ESP, keep your real sender and campaign content, and review the results in MailSlurp.

Catch the change before your audience does.

Schedule regular tests through your sending service and catch a drop in inbox placement. Compare runs, open a sender's history and identify the provider that changed.

Run a manual check before a campaign, set up recurring tests or trigger a run through the API. Your team can review every result and investigate spam scores in the web dashboard.

See the test workflow

Illustrative daily test results showing a drop in inbox placement and a rise in spam over time

Example test history showing a change in inbox placement.

Personal inbox coverage

Check Yahoo, Gmail, Outlook, Proton Mail and iCloud accounts to see where your consumer campaigns and notifications land.

Professional inbox coverage

Include Google Workspace and Microsoft 365. Business filtering can produce a different result from a personal account.

Get notified on inbox placement changes

Get inbox placement change alerts in Slack or Microsoft Teams. Keep your team informed when delivery shifts so you can investigate the affected sender or provider.

Test inbox placement from your sending platform

Sending a campaign manually? Follow the guide for your email platform.

Kit

SendGrid Shopify WooCommerce

Make inbox placement part of your workflow.

Create tests, send your campaign and retrieve provider results through the API. Add placement checks to your app, campaign tools or release workflow, with every run available in the web dashboard.

View API reference

MailSlurp inbox placement API

const apiKey = process.env.MAILSLURP_API_KEY!;

const run = await fetch("https://api.mailslurp.com/inbox-placement-tests", {
  method: "POST",
  headers: {
    "x-api-key": apiKey,
    "content-type": "application/json",
  },
  body: JSON.stringify({
    requestedSegment: "ALL_INBOXES",
    addressFormat: "NEWLINE",
    publicShareRequested: true,
    senderDomain: "example.com",
    fromEmail: "hello@example.com",
  }),
}).then((response) => response.json());

console.log(run.seedAddresses, run.trackingToken);

Make the next send better in every way.

Pair inbox placement with device rendering, Email Audit and domain monitoring. Check where your email lands, how it looks and what needs fixing.

See it on real devices

Email previews on phone, tablet and desktop clients

Preview the delivered email across Gmail, Outlook, Yahoo, Apple Mail and mobile or desktop clients, including light and dark mode.

Explore device rendering

Find content problems

Email Audit illustration showing message content checks

Catch broken links, missing images, accessibility findings and HTML issues with Email Audit before customers open your message.

Explore Email Audit

Keep your sender healthy

SPF, DKIM, DMARC and blocklist checks for a sending domain

Monitor SPF, DKIM, DMARC, MX and blocklist signals. Investigate sender-domain changes alongside placement results.

Explore domain monitoring

Email Quality

Check how your emails look and where they land.

100 client previews / month
25 inbox placement tests / month
Email audits, monitoring and warmup tools

$79/ month · USD

One person included

View package

Extra previews, warmup senders and activity billed separately.

Start in Sandbox for free

Inbox placement testing questions

Real account coverage, repeatable tests and the checks behind a better send.

What does an inbox placement test tell me?

MailSlurp gives you a seed list of real email accounts to test. Send your message to those addresses through your usual sending service and MailSlurp records where each copy lands: inbox, Promotions, spam or junk, or not received. A successful send means the receiving server accepted the email; a placement test shows what happened inside the mailbox. Read the inbox placement guide.

Does a pending or not-received result mean spam?

No. Pending means the provider result is still being checked. Not received means MailSlurp did not observe a matching message at that seed during the test window. Check that you sent to every current seed and included the exact test marker. Review the completed provider results separately; do not count missing results as inbox or spam.

Which personal and professional inboxes can I test?

Test across supported Gmail, Yahoo, Outlook.com, Hotmail, Proton Mail and iCloud personal accounts, plus Google Workspace and Microsoft 365 business accounts. Choose a personal, professional or mixed audience when creating the test. Coverage and test allowances depend on your plan. The current seed list shows the accounts included in that run, and results keep each provider and audience visible.

Can I test emails from my ESP?

Yes. Use your own email service provider (ESP) for scheduled checks, manual campaign tests or API-driven tests. Your email travels through your real sending platform and domain. The provider guides explain how to send a campaign or test email to the supplied seed list. Find your sending platform.

How can I automate inbox placement testing?

Connect your sending service and create a recurring schedule in MailSlurp. For custom workflows, use the API to create a test, get its seed addresses and tracking token, send your email, and retrieve provider results. You can also run a manual test whenever you need a one-off check. See the API workflow.

How are spam scores different from inbox placement?

Spam scores help identify filtering risk in your message. Inbox placement measures where the email actually arrived in each seed account: inbox, Promotions, spam or another folder. A low spam score does not guarantee inbox placement, so review both alongside content and domain findings. Promotions is shown separately from spam. Try a free spam test.

Can I monitor results over time and share them with my team?

Yes. The MailSlurp dashboard keeps test history and sender trends so you can compare inbox, spam, Promotions and not-received outcomes across runs. Open a sender to inspect provider health and previous tests. Export a report or create a share link when teammates need to review the same result.

Can I combine placement with device rendering and Email Audit?

Yes. Test placement, send the same email to a render inbox for real-client and device previews, and use Email Audit to check links, images, accessibility and HTML. These checks answer different questions: where the email landed, how it looks and which content issues need attention. Explore campaign quality assurance.

Your next email deserves the inbox.

Send a real test. See where it lands. Make the next send with the results in front of you.

Start testing for free

Gmail, Outlook and Yahoo logos beside a campaign email in the spam folder

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