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One-to-one · Inbox placement seeds

Inbox placement seeds

One row, in depth: what each tool does, the verified numbers, and who each suits.

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Instantly details read from its pricing and help pages on 15 and 17 October 2026.

Warmerly

Placement test, limited accuracy (no dedicated Gmail/Outlook seed list yet)

Gmail and Microsoft (Inbox Placement add-on, from $47 a month)

The short answer

Inbox placement testing, in one look.

Instantly sells a separate Inbox Placement add-on that tests Gmail and Microsoft (per its help centre) from $47 a month, with automated tests on the $97 tier. Warmerly includes a placement test on the account page, but today it sends to Warmerly's own warmup mailboxes, which accept almost everything, so the result is flagged "Limited accuracy" and does not feed health scores. A mode using other customers' real mailboxes is built but switched off. Last checked 19 October 2026.

Warmerly

Placement test, limited accuracy (no dedicated Gmail/Outlook seed list yet)

Gmail and Microsoft (Inbox Placement add-on, from $47 a month)

The picture

Drawn side by side.

What each placement test is

Where the test mail goes

Warmerly

A placement test

  • Cost: No separate charge stated in the product docs we read
  • Providers tested: Gmail, Outlook targets in the real-seed mode (off); today our own mailboxes
  • Seed list: None dedicated; table empty in production

An Inbox Placement add-on

  • Cost: Add-on: $47 a month (one-time tests) or $97 a month (plus automated); 2 free tests
  • Providers tested: Gmail and Microsoft (help centre); Gmail, Outlook, Yahoo (marketing page)
  • Seed list: Provided; ownership and size not published

Read the details below: the two tests are not built the same way.

How Warmerly does it

Warmerly, in detail.

A placement test exists and runs daily, but in production it is a degraded test against our own mailboxes, not a measurement of Gmail or Outlook placement.

01

What a test does

It sends one message from the mailbox's own SMTP to up to 4 targets (2 same provider, 2 other), subject "[Warmerly placement] <id>". After a wait (30 seconds on demand, 90 in the daily sweep) it checks INBOX, Promotions, Spam and Junk over IMAP and scores each result: inbox 100, promotions 60, spam 10, missing 0, then averages.

Warmerly product, checked 19 October 2026

02

No dedicated seed list yet

Real measurement needs seed mailboxes at Gmail, Outlook or Yahoo in the placement_seeds table. As of the doc's check on 2026-10-15 the table has never held a row in production, so every test falls back to our own warmup-pool mailboxes. The 57 non-degraded rows in production are demo-workspace seed data, not real runs.

Warmerly product, checked 19 October 2026

03

Why a degraded result is not a measurement

Our own mailboxes accept essentially everything, so the score is about 100 whatever the sender's real performance. In code a degraded run never writes health, is excluded from the spam score and the capacity quota, and the account page shows a "Limited accuracy" note. A trend is only shown when the two latest tests are the same kind.

Warmerly product, checked 19 October 2026

04

Real-mailbox seeds (built, off)

PLACEMENT_REAL_SEEDS defaults to off. When on, targets would be consenting Gmail or Outlook mailboxes of other customers already in the warmup network (2 per customer and 2 per mailbox per day), found by Message-ID header only, never reading subject or body. The doc says this was never run against production or a live Gmail or Outlook mailbox, and a Gmail "promotions" result is unproven.

Warmerly product, checked 19 October 2026

05

Where it runs and what else is checked

On-demand from the mailbox Health tab (about 45 to 60 seconds) and daily for up to 5 mailboxes per sweep, skipping any tested in the last 24 hours. DNS (SPF, DKIM, DMARC) is a separate check, every six hours.

Warmerly product, checked 19 October 2026

06

The 30-day inbox guarantee

The published guarantee refunds a month's fee if a mailbox shows no placement improvement between its first test and one on or after day 30, both run in Warmerly, with conditions. Support checks the test history by hand.

Warmerly product, checked 19 October 2026

How Instantly does it

Instantly, in detail.

Instantly has a separate paid Inbox Placement feature: seed-based tests, authentication and blacklist checks, with recurring tests and triggers on the higher tier.

01

What it tests

The help article says it evaluates whether emails land in the inbox or spam across different providers, analyses content for spam triggers, checks SPF, DKIM and DMARC, and monitors IPs and domains against 94 blacklists. It says the feature supports Gmail and Microsoft.

help.instantly.ai/en/articles/10147177-inbox-placement-feature · read 19 October 2026

02

Price and tiers

The plans overview lists Growth Inbox Placement at $47 a month (unlimited one-time tests) and Hypergrowth Inbox Placement at $97 a month (unlimited one-time and automated tests). The help article also says all users can run two free one-time tests. Automated tests can pause campaigns when placement drops below a set percentage.

help.instantly.ai/en/articles/10273259-instantly-plans-overview ; https://help.instantly.ai/en/articles/10147177-inbox-placement-feature · read 19 October 2026

04

Marketing page and blog differ from the help centre

instantly.ai/inbox-placement says the tool checks inbox, promotions or spam across Gmail, Outlook and Yahoo, monitors 400+ blacklists and uses SpamAssassin, with 2 free tests then unlimited tests on a paid plan. Its blog says seed addresses cover Gmail, Outlook, Yahoo and Apple Mail, results arrive in 5 to 10 minutes, and automated tests are in all Outreach plans from $37 a month.

instantly.ai/inbox-placement ; https://instantly.ai/blog/inbox-placement-testing · read 19 October 2026

What Instantly does not say

We looked, and found no statement on these. That is about its published pages only, not about the product.

  • Searched the Inbox Placement help article, the plans overview, instantly.ai/inbox-placement and the blog post for who owns or operates the seed mailboxes, how many there are, and an accuracy figure; found no statement. The two linked help articles (One-time Tests, Automated Tests) did not load when fetched, so we could not read them.
  • Searched instantly.ai/pricing for an Inbox Placement price; the $47 and $97 figures come only from the help-centre plans overview.
The numbers

Only what we could verify.

Inbox placement seeds: Warmerly and Instantly side by side. Warmerly is in the first column.
MeasureWarmerly
Inbox placement seedsPlacement test, limited accuracy (no dedicated Gmail/Outlook seed list yet)Gmail and Microsoft (Inbox Placement add-on, from $47 a month)
CostNo separate charge stated in the product docs we readAdd-on: $47 a month (one-time tests) or $97 a month (plus automated); 2 free tests
Providers testedGmail, Outlook targets in the real-seed mode (off); today our own mailboxesGmail and Microsoft (help centre); Gmail, Outlook, Yahoo (marketing page)
Seed listNone dedicated; table empty in productionProvided; ownership and size not published
Targets per testUp to 4Not published
Wait before reading result30 seconds on demand, 90 in daily sweep5 to 10 minutes (blog)
Blacklists monitoredSeparate blocklist checks94 (help centre) or 400+ (marketing page)
Accuracy flag"Limited accuracy" on degraded runsNo accuracy figure published
In practice

What it means for you.

Our reading of the facts above. Not a promise, and not the only reasonable reading.

1

Right now Instantly's tool measures something Warmerly's does not

Our reading: a test against dedicated seed mailboxes at Gmail and Microsoft is a real, if imperfect, sample. Warmerly's current test cannot tell you how Gmail treats your mail, which is why it is labelled and kept out of health scores.

2

Seed tests are a sample, not a verdict

Our reading: neither a seed list nor a handful of customer mailboxes reflects your actual recipients. Use any placement figure as one input beside replies, bounces and DNS results.

3

Cost versus coverage

Our reading: Instantly's add-on adds $47 to $97 a month to a plan. Warmerly's has no separate charge in the docs we read but, until real seeds are switched on, mainly checks that the send path works.

Who it suits

Pick the one that fits.

Warmerly

Warmerly is the better fit if

  • You want placement checks, DNS monitoring every six hours and warmup in one price and can accept that the placement test is currently a limited signal.
  • You prefer a clear label when a test is not a real measurement.
  • You are happy to wait for real-mailbox seeds, which are built but not yet switched on.

Instantly is the better fit if

  • You need placement tests against Gmail and Microsoft seed accounts today.
  • You want recurring tests with a trigger that can pause campaigns when placement drops.
  • You want tests from outside Instantly, for mail sent through other tools.
Questions
Does Warmerly test real Gmail and Outlook inboxes?

Not yet in production. The placement_seeds table has never held a row there, so tests use Warmerly's own warmup mailboxes and are marked Limited accuracy.

Why not just show the score?

Our own mailboxes accept almost everything, so the score is near 100 whatever your real placement. That is why degraded runs are kept out of health scores and the sending quota.

How much is Instantly's Inbox Placement?

Per its help centre, $47 a month for unlimited one-time tests or $97 a month for one-time and automated tests, with two free tests. Its blog gives $37 a month, so check at checkout.

What does Instantly's test check?

Where test emails land at Gmail and Microsoft per the help centre, plus content spam triggers, SPF, DKIM, DMARC and blacklists (94 per the help centre, 400+ per the marketing page).

Can any tool guarantee inbox placement?

No. Instantly's deliverability guide says so itself. Warmerly's guarantee is a refund if a mailbox shows no placement improvement at 30 days, with conditions.

Sources

Instantly pages were read on 19 October 2026. Plans and wording change, so check the vendor's own page before you decide. Warmerly details come from the product as it runs today.

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