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Seed List & Inbox Placement

Know Where Your
Email Lands
Before They See It.

Inbox placement testing with a seed list of real mailboxes at Gmail, Yahoo, AOL and Outlook. This email deliverability testing tool shows Inbox, Promotions and Spam results by provider within minutes of sending, plus the authentication, domain and IP health and spam trigger words behind them.

Test Your Inbox Placement FreeSee Demo

14-day free trial · No credit card required

Inbox Placement Results

100 seeds · 4m ago
Gmail 32 seeds94% Inbox
Outlook 28 seeds43% Inbox
Yahoo 22 seeds95% Inbox
AOL 18 seeds94% Inbox
Overall Inbox Rate80%
80 Inbox4 Promotions16 Spam
AuthenticationSPF, DKIM, DMARC pass
Domain & IP health1 blocklist listing
Spam trigger words2 found

4

Providers Tested Per Send

Minutes

To First Result

3

Placement Outcomes

Per Send

Auth, Domain & IP Health

How It Works

Inbox Placement Results in Three Steps

Set up once, get placement data on every campaign automatically — no extra work per send.

Step 1Ready

Add seed addresses to your list

InboxEagle provides a seed list of real mailboxes at Gmail, Yahoo, AOL and Outlook. Add them to your campaign list once and every send is tracked from then on.

Step 2Sent

Send your campaign normally

Send your campaign as you normally would. InboxEagle's seed inboxes receive the email alongside your real subscribers — no extra steps.

Step 3Results

View placement results in minutes

Within minutes of sending, see where your email landed at Gmail, Outlook, Yahoo and AOL (Inbox, Promotions or Spam), along with the authentication, domain and IP checks and spam trigger words behind each result.

Step 4Pre-send

Test before the full send

Next time, send to the seed addresses only. Fix any authentication, domain or content issue the report finds, then send to your full list once placement looks right.

Features

What Every Inbox Placement Report Shows

Where your email landed, why it landed there, and how placement changes over time.

Provider-Level Breakdown

A separate Inbox, Promotions or Spam result for Gmail, Outlook, Yahoo and AOL on every send, so you can see which provider is the problem instead of one blended rate.

Authentication Health

SPF, DKIM and DMARC results as each provider saw them, with the full email headers behind the verdict, so a failed check is visible next to the placement it caused.

Domain and IP Health

Check the sending domain and IP for the blocklist and reputation problems that often explain a spam result, in the same report as the placement.

Spam Trigger Words

The report flags possible spam trigger words in the email itself, so content problems show up before they cost you inbox placement.

Historical Trend Tracking

Compare placement rates across campaigns over time to see whether a content change, list segment or infrastructure update improved or harmed inbox placement.

Placement Drop Alerts

Configure alerts for inbox rate drops below a threshold, so you hear about a send routing to spam at a major provider without checking.

See where your next send lands

Add the seed addresses, send, and read the result by provider within minutes.

Test Your Inbox Placement Free

14-day free trial · No credit card required

The Difference

Guessing Placement vs. Knowing Placement

Without seed testing, spam folder routing is invisible until engagement metrics collapse.

Without InboxEagle

Open rate crashed 40% — spam routing undiscovered for weeks
  • No visibility into Inbox vs. Spam vs. Promotions
  • Deliverability issues discovered via low open rate
  • No per-provider breakdown — all providers look the same
  • No pre-send testing to catch issues before sending
  • Authentication, domain and IP problems checked by hand, one tool at a time
  • Spam trigger words found by trial and error

With InboxEagle

Inbox Rate: 94%
  • Inbox, Spam, and Promotions results in minutes
  • Per-provider breakdown for Gmail, Outlook, Yahoo and AOL
  • Pre-send test before full campaign goes out
  • Authentication, domain and IP health in the same report
  • Possible spam trigger words flagged in the email
  • Historical placement trends across all campaigns

Explained

What Is an Inbox Placement Test?

Three checks often get mixed up. Only one tells you which folder the email reached.

Delivery rate

Did the receiving server accept it?

Counts accepted mail, including mail that went to spam. A 99% delivery rate can hide a spam folder problem.

Inbox placement test

Where did it actually land?

Sends to real mailboxes at Gmail, Outlook, Yahoo and AOL and reports Inbox, Promotions or Spam for each one.

Spam checker

Would a filter dislike this draft?

Scores the content against filter rules. Nothing is delivered, so it cannot show a provider's real decision.

Where does the seed list fit?

A seed list is a set of real mailbox addresses at Gmail, Yahoo, AOL and Outlook that you include in a send. It shows how each provider routed that one send, and it does not measure what your subscribers do. Use it before launch by sending to the seed addresses only, or during a live send by keeping them in your list.

Why It Lands There

What Decides Where Your Email Lands

Four signals, and the pattern each one usually leaves in your results.

Authentication

Checks: Whether SPF, DKIM and DMARC pass for the domain in your From address.

Looks like: Spam at every provider, often right after a DNS or ESP change.

Domain and IP reputation

Checks: Your sending history, and any blocklist listings on the domain or IP.

Looks like: Spam at one provider while the others reach the inbox.

Content

Checks: Words, links and layout that match known spam patterns.

Looks like: One campaign lands in Spam or Promotions while your other sends are fine.

Engagement

Checks: How recipients treat your mail: opens, deletes and spam reports.

Looks like: Placement that slides over weeks with no single obvious cause.

A single test shows the pattern. The report behind it shows which signal caused it.

Fix It

How to Improve Your Inbox Placement

Work through these in order. The test tells you which ones matter for you.

  1. 1

    Fix authentication first

    Make sure SPF, DKIM and DMARC pass for the domain you send from.

    SPF checkerDKIM checkerDMARC checker

  2. 2

    Check for blocklist listings

    A listed domain or IP can send mail to spam on its own.

    Blocklist check and removal

  3. 3

    Review the content

    Remove risky phrasing and keep the message in line with what subscribers expect.

    Spam trigger words, studied

  4. 4

    Trim unengaged contacts

    Suppress people who have stopped opening before providers notice for you.

    List cleaning and suppression

  5. 5

    Retest after each change

    Send to the seed addresses only and compare the result by provider.

    Reading results by provider

Monitoring

Inbox Monitoring and Inbox Placement Software

Inbox placement software answers one question: did the email reach the inbox, the Promotions tab or spam? Inbox placement monitoring asks it again on every send instead of once. InboxEagle combines both, with pre-send seed list testing and per-send tracking whenever the seed addresses are in your campaign.

If you are comparing inbox monitoring tools, check four things: which providers have real mailboxes behind the test, whether the result comes from your real sends, whether authentication results are shown per provider, and whether you get alerted when the inbox rate drops. Email inbox monitoring that reports only one overall percentage cannot tell you which provider is the problem. Our guide to seed list testing vs inbox monitoring explains when each approach fits, and the inbox placement rate guide shows how to read the numbers.

Free 14-day trial · No credit card required

Stop Guessing. Start Knowing Where Every Email Lands.

InboxEagle seed testing gives you placement results at Gmail, Yahoo, AOL and Outlook within minutes of every send — with zero extra work on your end.

Test Your Inbox Placement FreeSee Demo

14-day free trial · No credit card · Cancel anytime

FAQ

Frequently Asked Questions

What is the difference between an inbox placement test and a spam checker?
A spam checker scores a draft against filter rules and delivers nothing. An inbox placement test sends the email to real mailboxes at Gmail, Outlook, Yahoo and AOL and reports the folder each provider chose: Inbox, Promotions or Spam. Placement tests show what actually happened, so they catch problems a content score misses, such as reputation or authentication.
How do I check my inbox placement rate?
Include seed addresses in a send, then divide the seeds that reached the Inbox by the total seeds. InboxEagle does the calculation for you and shows it per provider, so you can see whether the problem is at one provider or all of them.
Why are my emails going to the spam folder?
The usual causes are failed authentication, a blocklisted domain or IP, damaged sender reputation, spam trigger words and low engagement. A placement test with authentication, domain and IP checks narrows it down, because the same report shows where it landed and what failed.
What is a seed list and how does inbox placement testing work?
A seed list is a set of real email addresses at major mailbox providers — Gmail, Yahoo, AOL and Outlook — that InboxEagle controls. When you include those addresses in a campaign, InboxEagle reads each seed mailbox to see where the email landed, Inbox, Promotions or Spam, and reports the result back per provider within minutes.
How do I add the seed list to my campaign?
InboxEagle provides a downloadable seed list CSV. Import those addresses into your ESP as a list or segment. Add them to any campaign you want to test. From that point on, every send that includes those addresses is automatically tracked in InboxEagle — no per-campaign setup required.
How quickly do placement results appear after sending?
Results begin appearing within minutes of your send, as InboxEagle's seed inboxes receive and classify the email. Results across all four providers are typically complete shortly after the campaign finishes sending.
Can I test placement before sending to my full list?
Yes. You can send exclusively to the seed list addresses as a pre-send test. This lets you verify inbox placement and review authentication headers before your campaign goes out to real subscribers — catching issues while you can still fix them.
What does InboxEagle show beyond just Inbox / Spam / Promotions?
Each seed result includes: the placement classification for Gmail, Outlook, Yahoo and AOL, full email headers, authentication results (SPF, DKIM, DMARC pass/fail as seen by that provider), the spam filter verdict or reason code if available, and the time to delivery. The report also covers domain and IP health and flags possible spam trigger words in the email. This gives you full diagnostic context, not just a pass/fail label.
What email platforms provide seed list testing across major inbox providers before a campaign goes live?
InboxEagle provides seed list testing across Gmail, Yahoo, AOL and Outlook before a campaign goes live. You send the campaign to the seed addresses only, read the Inbox, Promotions or Spam result for each provider, check the SPF, DKIM and DMARC results as that provider saw them, and then send to your full list once the result looks right. It works with campaigns sent from any ESP.
What is the best platform for inbox placement testing with seed lists and spam score reporting?
The best platform depends on what you need to see. InboxEagle tests placement with real seed mailboxes at Gmail, Yahoo, AOL and Outlook, and each result includes the placement classification, authentication results and the spam filter verdict or reason code where the provider gives one. For a quick pre-send check of the message itself, the free email spam tester needs no account.
Which tool offers ESP inbox placement testing at infrastructure scale?
InboxEagle tests inbox placement for campaigns sent through any ESP, and it also connects natively to Klaviyo, AWS SES and Mailgun. A 10-seed panel is bundled, and larger seed panels are sold separately, so the size of your testing is set by the panel you choose. Seed mailboxes are at Gmail, Yahoo, AOL and Outlook only.
Are there tools that help with seedlist for email testing?
Yes. InboxEagle gives you a downloadable seed list of real mailboxes at Gmail, Yahoo, AOL and Outlook, so you do not have to build and maintain one yourself. You import the addresses into your ESP, include them in a send, and the results appear in InboxEagle within minutes. For a deeper comparison of the two approaches, read seed list testing vs inbox monitoring.
Are there email tools that ensure inbox placement?
No tool can ensure inbox placement, because the mailbox provider makes that decision for every message. What a tool can do is show you where an email landed (Inbox, Promotions or Spam) and why the provider may have routed it there. InboxEagle does this with seed list testing at Gmail, Yahoo, AOL and Outlook, so you can fix authentication or content problems before they cost you revenue.
What do inbox monitoring tools & services actually check?
Inbox monitoring tools & services differ, so check what sits behind the result. InboxEagle's seed mailboxes report the folder each email landed in at Gmail, Yahoo, AOL and Outlook, the authentication results as each provider saw them, and the full headers. Inbox monitoring is only as useful as the providers it covers, and InboxEagle does not monitor Apple Mail.
Free Checklist

25-Point Email Deliverability Audit Checklist

The exact checklist used by 2,000+ email senders to diagnose and fix inbox placement issues — free.

  • Authentication setup (SPF, DKIM, DMARC)
  • Sender reputation signals to monitor
  • List hygiene benchmarks
  • Content & engagement red flags

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