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Instantly inbox placement test 2026: how to run the test, what scores mean per provider, how to diagnose root causes, and how to fix poor placement before launching campaigns.
James Whitfield
Lead gen agency owner, 50+ campaigns/month · Updated June 24, 2026
Last updated: June 2026 · James Whitfield, Lead gen agency owner, 50+ campaigns/month
TL;DR — 5 things to know before reading
Inbox placement testing is the quality gate that separates practitioners who reach inboxes from those who send campaigns into spam folders. Most cold email failures at scale are not caused by bad copy or wrong ICPs — they are caused by infrastructure problems that a 5-minute placement test would have caught before the campaign started.
After running 50+ campaigns per month, the pattern is consistent: senders who test before every campaign maintain open rates above 30%; senders who skip the test and launch directly from campaign setup experience open rates in the 8–15% range on the same lists and the same copy, because 30–60% of their sends are landing in spam or promotions without a single real prospect seeing them. The placement test is not optional — it is the starting condition for any campaign worth running.
Instantly includes a built-in deliverability test that covers Gmail, Outlook, Yahoo, and other major providers. The test uses a seed network of controlled email addresses monitored specifically for placement. This guide covers the complete inbox placement testing system: the technical mechanics, what each provider's score means, how to diagnose the root cause of poor placement, how to fix each cause specifically, and how to build a testing cadence that catches problems before they affect live campaigns. Quarvio provides verified contacts that keep bounce rates below 2% — high bounce rates are one of the fastest ways to destroy the domain reputation that placement tests measure. Aimfox runs parallel LinkedIn outreach from the same contact data.
The gap between a 30% open rate and a 10% open rate is not always explained by subject lines or send timing. In many cases, the gap is explained by placement: the email landing in spam means zero opens regardless of the subject line. A placement test eliminates the ambiguity before the campaign starts.
Each email provider runs its own scoring algorithm. Gmail's Promotions tab is distinct from spam — an email in Promotions is not blocked but is in a folder most recipients rarely check for B2B correspondence. Outlook evaluates sender authentication more strictly than Gmail for first-time senders. Yahoo has historically been more aggressive in spam classification for new sending domains.
A sender with three domains — Domain A scoring 92% primary on Gmail, Domain B scoring 45% spam on Outlook, Domain C scoring 78% primary across all providers — has three very different performance profiles. Without per-domain placement testing, all three look identical in the campaign setup: three sending domains, all connected, all with warmup scores above 80. The placement test is the only way to surface the difference before it shows up as a 15% open rate on the Domain B campaigns.
Inbox placement is determined by three independent layers, each affecting score in different ways:
Layer 1 — Infrastructure (DNS authentication): SPF, DKIM, and DMARC records authorize sending servers to send on behalf of your domain and authenticate each email's origin. When these records are missing, misconfigured, or inconsistent, email providers apply default suspicion to every email from the domain. A single missing DMARC record is enough to drop Gmail placement from 90% to 40%.
Layer 2 — Domain reputation: The cumulative history of emails sent from your domain, including: spam complaint rates, bounce rates from previous sends, time since domain registration, and whether the domain appears on any blacklists. New domains have no reputation; high-complaint domains have poor reputation. Warmup builds reputation by generating positive engagement signals (opens, replies) before any cold sending begins.
Layer 3 — Content signals: The email's subject line, body copy, link quantity, HTML formatting, and image use all generate signals that spam filters evaluate. Spam trigger words, heavy HTML formatting, multiple links, and images without alt text each lower the content score. Even the ratio of text to HTML in the email body affects content scoring.
A placement test result that shows 30% spam placement may be caused by Layer 1 (DNS problem), Layer 2 (reputation problem), Layer 3 (content problem), or a combination. The diagnostic approach is to isolate which layer is causing the problem before attempting to fix it.
Run a placement test in these specific situations:
Before every new campaign: This is non-negotiable. Even if the sending domain has been used successfully for weeks, a new campaign with new copy requires a new test — content scoring affects placement independently of infrastructure and reputation.
After any email copy change: Changing the subject line, adding or removing links, changing the CTA structure, or adjusting the body length all require a new placement test. The infrastructure may be healthy; the new content may not be.
After adding new sending inboxes: New Inframail inboxes or any newly connected sending accounts should be tested individually before being added to active campaigns. A misconfigured new inbox affects the entire campaign's delivery.
After any infrastructure change: DNS record updates, domain changes, switching sending providers, or changing IP addresses all require fresh placement tests. DNS propagation issues can cause intermittent authentication failures that only show up in placement tests.
After a period of elevated spam complaints: If campaign analytics or Google Postmaster Tools show spam complaint rates above 0.1%, run a placement test to quantify how much the reputation damage has affected inbox placement across providers.
After recovering from a domain blacklisting: Once a domain is removed from a blacklist, run a placement test to confirm placement has recovered before resuming sends. Blacklist removal does not automatically restore inbox placement — reputation recovery takes additional time.
On a monthly maintenance schedule: Even for domains with no active campaigns, a monthly placement test confirms the domain's health and catches any reputation degradation that might happen due to external factors (IP range issues, domain age signals, or similar).
Instantly's deliverability test sends your email content to a network of controlled "seed" email addresses. These are real email accounts created and monitored specifically for placement testing purposes.
The seed network includes addresses at Gmail, Outlook, Yahoo, and typically 10–20 additional providers. The test monitors which folder each seed address received the email in: primary inbox, promotions tab (Gmail-specific), or spam.
Results typically appear within 2–5 minutes of running the test. The results show:
The seed address results do not perfectly replicate real-world placement for every individual prospect — individual email security configurations can vary significantly from the seed network. However, seed-based placement tests are the most reliable method available for pre-campaign deliverability verification and are accurate enough to catch the major infrastructure and content problems that cause widespread spam routing.
Sub-step 1.1: Log in to your Instantly account and navigate to the Deliverability Test feature.
This feature may appear in the main navigation, in the Tools section, or in your account dashboard depending on your Instantly plan tier. On Growth plans, the deliverability test is accessible from the main navigation. On Hypergrowth and above, it may be in the Tools or Utilities section.
Sub-step 1.2: Confirm your Instantly plan includes the deliverability test.
Not all Instantly plan tiers include the same deliverability testing features. If the deliverability test is not visible in your Instantly account, check your current plan limits. The Growth plan at $30/month includes basic deliverability testing; Hypergrowth and above include more advanced deliverability tools.
Sub-step 1.3: Click Create New Test or New Test to begin the setup.
Sub-step 1.4: Name the test for future reference.
Use a naming convention that identifies the inbox being tested and the campaign the copy is from. Example: [Inbox Name] - [Campaign Name] - [Date]. This allows you to track test history and compare results over time.
Benchmark: The deliverability test feature is accessible within 60 seconds of logging in if your plan includes it.
Failure mode: If you cannot locate the deliverability test, you may be on a plan tier that does not include it, or you may need to upgrade. Check Instantly's current plan features page rather than using an outdated guide for navigation paths, as Instantly updates its navigation periodically.
This is the most critical setup step. The value of a placement test depends entirely on how closely the test email matches the actual campaign email.
Sub-step 2.1: Use your exact step 1 subject line for the test.
Copy the exact subject line from your campaign's first email step. Do not use a placeholder or a simplified version — subject lines with trigger words, personalization tokens, or specific phrasing each affect spam filter scoring in ways that a generic subject line will not reveal.
Sub-step 2.2: Paste your exact step 1 body copy into the test body field.
Include all formatting, links, and signatures exactly as they appear in the campaign. Spam filters evaluate the full email body, including the HTML structure, link count, and text-to-HTML ratio.
Sub-step 2.3: Review the email for common content issues before running the test.
Before running, do a quick scan for known content issues:
Fixing obvious content issues before running the test saves time compared to getting a spam result and then diagnosing the cause.
Sub-step 2.4: If testing plain text vs. HTML, run two separate tests.
Gmail's spam filter scores HTML and plain text emails differently. If your sequence uses HTML formatting (buttons, images, or colored text), also run a plain text version of the same copy to compare placement. A significant placement improvement in plain text compared to HTML indicates the formatting itself is contributing to spam placement.
Benchmark: The test email should be identical to the first email in the campaign in every way — subject, body, links, formatting, and signature.
Failure mode: Running the placement test with a generic "Hello, this is a test" body and concluding the infrastructure is clean. If the real campaign email has trigger words or problematic formatting, the generic test completely misses those content scoring issues. The domain may place well on a generic test and land in spam on the actual campaign.
Sub-step 3.1: In the account selector, choose the specific sending inbox you intend to use for the campaign.
If you are running campaigns from multiple inboxes, each inbox must be tested separately. A placement result from Inbox A does not apply to Inbox B — each inbox has its own IP address, warmup history, and sending reputation.
Sub-step 3.2: For multi-inbox campaigns, test a representative sample.
If you have 10 inboxes in your campaign rotation and all were provisioned from the same Inframail batch at the same time with the same domain, testing 2–3 representative inboxes from that batch is sufficient. If inboxes were provisioned across different batches, domains, or time periods, test at least one from each group.
Sub-step 3.3: Test newly added inboxes individually.
Any inbox added to Instantly in the past 30 days should be tested individually before being included in campaign rotation, regardless of warmup score. Warmup score and inbox placement score measure different things: warmup score measures engagement signals generated by the warmup process; placement score measures how live email providers actually classify emails from this inbox today.
Benchmark: Test each sending inbox at least once before its first campaign. For ongoing campaigns, test any inbox that shows a warmup score drop of 5+ points since its last test.
Failure mode: Selecting the wrong inbox for the test — testing Inbox A but running the campaign from Inbox B. The test result is valid but not applicable to the campaign that will actually send. Confirm the inbox selected in the test matches the inbox configured in the campaign sending settings.
Sub-step 4.1: Review the test configuration one final time: confirm the subject line matches, body copy is complete, and the sending account is correct.
Sub-step 4.2: Click Run Test or Send Test.
Instantly distributes the test email to its seed network immediately. The seed addresses are spread across geographic regions and email providers, which is why results take 2–5 minutes — some seed addresses take longer to process than others.
Sub-step 4.3: Do not close the browser tab or navigate away while the test runs.
The test status updates in real-time. Closing the tab does not cancel the test, but navigating away may require you to return to the deliverability test dashboard to see results.
Sub-step 4.4: Note the test start timestamp.
Record when you ran the test in your test log (see configuration reference table). This creates a historical record for comparing placement over time and identifying when placement degraded.
Benchmark: Results appear within 2–5 minutes for 90%+ of tests. If results have not appeared after 10 minutes, something may have gone wrong with the test send itself.
Failure mode: Running the test and checking results immediately (30 seconds after clicking "Run Test"). The seed network results are not instantaneous — checking results before all seeds have reported will show an incomplete picture that may look worse than the final result.
Sub-step 5.1: Start with the overall placement percentage.
The headline number is the aggregate primary inbox placement across all seed addresses. Apply this threshold:
| Placement score | Status | Action |
|---|---|---|
| 90%+ primary inbox | Excellent | Launch campaign as configured |
| 80–89% primary inbox | Good | Acceptable for launch; monitor open rate daily in first week |
| 60–79% primary inbox | Concerning | Investigate and fix before launching |
| Below 60% primary inbox | Critical | Do not launch — fix infrastructure first |
Source: Woodpecker cold email infrastructure guide — verified June 2026
Sub-step 5.2: Break down placement by email provider.
Never stop at the overall number. The provider breakdown reveals patterns that the aggregate hides:
Gmail: The most important provider for B2B cold email. Gmail uses the Promotions tab as a middle ground — not spam, but lower-engagement territory for business email. A Gmail result of 30% primary / 50% promotions / 20% spam is very different from 50% primary / 50% spam with no promotions.
Gmail promotions placement is primarily driven by email formatting and the presence of commercial signals (multiple links, unsubscribe language prominent in the body, HTML buttons). Plain text emails with one or zero links almost never route to Gmail promotions.
Gmail spam placement is primarily driven by: missing authentication records (DMARC especially), domain reputation (spam complaint history), and strong spam trigger words in content.
Outlook: Microsoft's spam filters are more strictly authentication-focused than Gmail for cold outreach. Outlook (including Microsoft 365) applies extra scrutiny to new sending domains and shows less tolerance for missing authentication than Gmail. A domain showing 100% primary on Gmail and 60% spam on Outlook often has an authentication issue that Gmail is being more lenient about.
Yahoo: Yahoo's spam filters tend to be more aggressive than Gmail's for cold outreach and less forgiving of content triggers. A Yahoo spam result often indicates content issues that Gmail's algorithm is tolerating but Yahoo's is not.
Other providers: Results from Yahoo, Hotmail, ProtonMail, and smaller providers are useful secondary signals. If all major providers show good placement but one minor provider shows spam, the minor provider's result is a lower-priority issue.
Sub-step 5.3: Look for provider-specific patterns in the results.
| Pattern | Most likely cause |
|---|---|
| Spam on all providers | Authentication problem (SPF/DKIM/DMARC) or domain blacklisted |
| Spam on Gmail only | Content signals (formatting, links, trigger words) |
| Spam on Outlook only | Authentication issue or domain reputation specifically with Microsoft |
| Promotions on Gmail, inbox elsewhere | Email formatted like marketing content (HTML-heavy, multiple links) |
| Variable results (inbox and spam mixed) | IP reputation issue or inconsistent sending infrastructure |
| 0% primary on new inbox | Domain or inbox not yet warmed; sending from day-0 inbox |
Benchmark: The ideal result is 90%+ primary across all major providers. Accept 80% if the spam percentage across all providers combined is below 5%.
Failure mode: Looking only at the overall number and missing a provider-specific pattern. A 75% overall score where Gmail shows 90% primary and Outlook shows 40% primary and 50% spam is a critical Outlook-specific problem that the 75% average obscures.
Diagnosing which layer (infrastructure, reputation, or content) is causing poor placement requires a systematic process.
Sub-step 6.1: Verify DNS authentication records first.
Check that SPF, DKIM, and DMARC records are correctly configured for the sending domain. Use an external DNS lookup tool or the authentication report visible in Instantly's deliverability results.
The Mailgun SPF, DKIM, and DMARC setup guide describes exactly what each record should contain. For Inframail inboxes, these records are auto-configured — if they show as missing, the Inframail provisioning may not have completed correctly or DNS changes may have been made manually after provisioning.
Sub-step 6.2: Check the sending domain against blacklists.
Navigate to MXToolbox blacklist checker and enter your sending domain. If the domain appears on any major blacklist, that is almost certainly the cause of widespread spam placement. A blacklisted domain requires delisting before any placement test will show improvement.
Sub-step 6.3: Check domain reputation in Google Postmaster Tools.
Navigate to Google Postmaster Tools with your sending domain registered. The domain reputation display (low, medium, high, very high) directly correlates with Gmail placement. A "low" reputation domain will route a high percentage of sends to spam regardless of content quality.
Sub-step 6.4: Isolate content issues by testing the same inbox with stripped copy.
If DNS is correct, the domain is not blacklisted, and reputation is medium or high, but placement is still poor, content is the likely cause. Create a test version of the email with all links removed, plain text only, no HTML formatting, and no signature block. Run a placement test with this stripped version.
If stripped copy produces significantly better placement than the full campaign email, the difference identifies the content element causing the problem. Add elements back one at a time (first the signature, then one link, then formatting) and retest after each addition to isolate the specific trigger.
Benchmark: Root cause diagnosis takes 15–30 minutes for a systematic isolate-and-test approach. A practitioner who skips diagnosis and immediately edits copy may change the wrong element and see no improvement.
Failure mode: Assuming the content is the problem and rewriting copy when the actual issue is a missing DMARC record. Always check DNS authentication before touching copy.
For Inframail inboxes, authentication is auto-configured during provisioning. If authentication shows as missing:
For non-Inframail sending domains, follow the Mailgun SPF, DKIM, and DMARC setup guide to add the correct records in your DNS management panel.
After adding or fixing authentication records, wait 30–60 minutes for DNS propagation before retesting.
Low reputation recovery requires sending positive signals over time — it cannot be fixed with a single change. Steps to recover:
Benchmark: After the correct fix is applied, a retest should show improvement within 30–60 minutes for DNS and content issues. Domain reputation recovery takes weeks, not hours.
Failure mode: Applying a fix and launching the campaign before retesting. Always retest after fixing to confirm the fix worked. A fix that did not actually resolve the problem will only be discovered after the campaign has sent and damaged real prospect relationships.
A systematic testing cadence catches placement problems before they affect live campaigns.
Sub-step 8.1: Create a testing log.
Maintain a spreadsheet or document with one row per placement test:
Sub-step 8.2: Set up recurring tests for active inboxes.
For inboxes running active campaigns, schedule a placement test once per week. Set a calendar reminder to run the test every Monday or the first business day of each week. This catches reputation or infrastructure degradation before it affects the week's send volume.
Sub-step 8.3: Define escalation thresholds.
Decide in advance what placement scores trigger what actions:
Sub-step 8.4: Test all new inboxes before their first campaign assignment.
Add inbox placement testing as a required step in your inbox onboarding process. Before any new Inframail inbox is added to a campaign rotation, it must pass a placement test with 80%+ primary inbox placement. This is non-negotiable regardless of warmup score.
Benchmark: A well-maintained testing cadence identifies placement problems within 7 days of their onset, rather than after 2–4 weeks of sending with degraded delivery.
Failure mode: Running placement tests only when something goes wrong (open rates drop, someone flags a problem). Reactive testing allows problems to compound for weeks before they are diagnosed.
| Setting | Value | Notes |
|---|---|---|
| Minimum primary inbox score | 80% | Below this: fix before launching |
| Excellent score threshold | 90%+ | Safe to launch with confidence |
| Acceptable promotions (Gmail) | Below 30% of total | Higher: strip formatting |
| Maximum spam at launch | 5% across all providers | Higher: do not launch |
| Warmup score minimum | 80+ per inbox | Below 80: deliverability risk |
| Max spam complaint rate | Below 0.1% | Google Postmaster threshold |
| Blacklist check frequency | Monthly minimum | Weekly when experiencing issues |
| DNS records required | SPF + DKIM + DMARC | All three must be active and resolving |
| Min warmup before sending | 14–21 days | 28+ days for new domains |
| Test frequency | Before every campaign | Plus all trigger events listed above |
| Test log retention | Indefinite | Historical data for diagnosing regression |
When a campaign uses multiple inboxes in rotation, run the placement test from each inbox with the same email content. If one inbox shows significantly different results than the others (e.g., all inboxes show 90% primary except one that shows 50% spam), the problem is specific to that inbox — either its individual IP reputation or warmup history. Remove the underperforming inbox from the rotation and investigate.
Run two tests simultaneously: one with your full HTML campaign email, one with a plain text version containing the same copy. Compare results. The difference between the two tests quantifies the placement cost of your email's HTML formatting. If plain text places 30 percentage points better, the email's formatting is the primary driver of placement issues.
For B2B cold email sequences, plain text nearly always outperforms HTML on placement. A well-targeted plain text sequence beats a beautifully formatted HTML campaign every time from an inbox placement standpoint.
Whenever you make any DNS change to a sending domain (adding a record, updating an existing one, or changing DNS providers), run a placement test immediately after and again 24 hours later. DNS caching at various provider levels means authentication checks may still reference old records for several hours. A 24-hour retest confirms the change has fully propagated and placement is stable.
If you maintain a test log (see Step 8), you can graph placement scores over time per inbox. Gradual degradation (90% → 85% → 78% → 72% over 8 weeks) indicates progressive reputation erosion, typically from slowly accumulating spam complaints or gradual IP reputation decline. This pattern is much easier to catch and reverse early than to recover after placement has collapsed to 40%.
For every campaign, record both the pre-launch placement test result and the actual campaign open rate after 7 days. Over time, this correlation data shows how accurately placement tests predict real-world inbox performance for your specific ICP and sending infrastructure. Most practitioners find that campaigns with 90%+ placement scores achieve 35–55% open rates, while campaigns at 75% placement achieve 18–28% open rates — confirming that each percentage point of placement improvement corresponds to roughly 0.5–0.7% open rate improvement.
Some subject line formats trigger content scoring more than others. Run placement tests with your actual campaign subject line and with alternative formats (plain statement vs. question vs. forward-style subject) to see if the format itself affects placement, independent of the email body. This is particularly useful for campaigns targeting Gmail-heavy audiences where the promotions tab routing is sensitive to subject line format.
Placement tests are the most reliable pre-campaign tool available, but they have specific limitations practitioners should understand:
They do not predict individual prospect placement: Each recipient's email security configuration differs from the seed network. Corporate email systems with third-party security tools (Proofpoint, Mimecast, Barracuda) may classify emails differently from the seed addresses. A 90% placement test result means the seed network shows 90% primary, not that every prospect will see the email in their primary inbox.
They do not reflect warmup quality: A warmed inbox with legitimate positive engagement signals from the warmup period may outperform what the placement test predicts, because warmup-generated reputation signals take time to build and are not fully reflected in a single test. Conversely, an inbox with poor warmup quality may pass a placement test (because the test evaluates the domain's authentication, not the inbox's engagement history) but still underperform in real campaigns.
They do not diagnose recipient-level filtering: Some prospects have individual spam rules or security software that routes all unsolicited email to spam regardless of domain reputation. These individual-level filters are invisible to placement tests.
They do not measure list quality: A perfect placement score on a campaign with a low-quality, unverified contact list will produce high bounce rates that damage placement over time. Placement tests measure outbound capability; list quality from Quarvio determines whether that capability is preserved or eroded by the contacts you are sending to.
Symptom: After clicking "Run Test," the test result remains in pending status for longer than 10 minutes.
Cause: The test email may not have been sent successfully from the selected inbox. This is typically caused by a connection issue between Instantly and the sending inbox — the inbox may have lost its active connection.
Fix: Navigate to Email Accounts in Instantly and check the connection status of the inbox you selected for the test. If it shows a yellow or red status (disconnected or error), reconnect the inbox before running the test again. For Inframail inboxes, verify the inbox is still active in the Inframail dashboard before reconnecting in Instantly.
Symptom: The placement test shows very good placement at Outlook and most providers, but Gmail shows nearly all sends routing to spam or promotions.
Cause: This Gmail-specific problem indicates a content or reputation issue that Gmail's filters classify more strictly than Outlook's. The most common causes are: HTML-heavy formatting that triggers Gmail's Promotions routing, a domain on Gmail's internal sender reputation list as low-quality, or the sending IP flagged by Gmail specifically.
Fix: First, check Google Postmaster Tools for the sending domain's reputation. If reputation shows as "low," Gmail placement will remain poor until reputation recovers (see Step 7, reputation fix). If reputation is "medium" or "high," the issue is content — strip HTML formatting, reduce to one link, and retest with plain text copy.
Symptom: The placement test shows spam placement across all major providers simultaneously.
Cause: This universal spam pattern almost always indicates an authentication problem (DMARC missing or misconfigured) or a domain blacklisting. Universal spam placement is rarely caused by content alone — content issues typically affect specific providers more than others.
Fix: Immediately check MXToolbox blacklist checker for the sending domain. Also verify SPF, DKIM, and DMARC records using the Mailgun SPF, DKIM, and DMARC setup guide as reference. For Inframail inboxes, log in to the Inframail dashboard and confirm DNS records show as active. Do not launch any campaigns until universal spam placement is resolved.
Symptom: Stripping links from the test email improves placement from 35% to 65% primary, but the goal is 80%+ and you need at least one link in the campaign.
Cause: The link domain or the link destination has a poor reputation. Email security tools evaluate not just the sender domain but also the domains of any links included in the email. A link pointing to a domain on a blocklist, a recently registered domain, or a domain associated with marketing activity will drag down placement even when a single link is present.
Fix: Check the domain of every link you intend to include in the campaign on MXToolbox blacklist checker. If the link destination domain is clean, try using a link shortener or URL redirect on a clean domain to see if the destination domain is the issue. Also consider using a plain text URL with no hyperlink formatting — some spam filters score plain text URLs more favorably than HTML anchor tags.
Symptom: The pre-launch placement test shows excellent results, but after launching the campaign, open rates are far below what the placement score would predict.
Cause: The placement test reflects seed network results; real-world prospect placement can differ. Several factors explain the gap: the campaign contacts use email providers with stricter security (corporate email systems with additional filtering layers), the contacts are in companies that have blocked the sending domain in their corporate email policy, or the contacts have individual spam filters set to aggressive.
Fix: This is not a placement test failure — it is a reminder that seed-based testing has limits. Review the per-provider breakdown in the test results. If corporate Outlook (Microsoft 365) placement was lower than consumer Outlook placement, corporate email security is likely adding filtering. Consider running an inbox placement test specifically on an Outlook/Microsoft 365 seed if your ICP uses corporate Microsoft 365 extensively. Also check bounce rate in Instantly — if bounce rate is above 3%, list quality is causing delivery failures that look like placement issues.
Symptom: Gmail shows 70% primary, Outlook shows 90% primary, Yahoo shows 40% primary, other providers are mixed.
Cause: Mixed provider results without a clear pattern often indicate IP-level reputation issues rather than domain or content issues. The sending IP may have a different reputation at different providers based on historical send patterns from that IP range.
Fix: Check the sending IP (not just the domain) on MXToolbox blacklist checker. For Inframail inboxes, the IP is managed by Inframail's Microsoft 365 infrastructure — if the IP shows on a blacklist, contact Inframail support to investigate. Also reduce campaign send volume on the affected inbox temporarily, as high send volumes on a single IP accelerate reputation degradation at providers where the IP's reputation is already marginal.
Symptom: A newly provisioned Inframail inbox, connected to Instantly with warmup running, shows 100% spam placement on the first test.
Cause: This is expected for brand new inboxes on brand new domains. A domain registered days ago with no sending history has no reputation with email providers. Spam filters default to high suspicion for unknown domains. The warmup process exists specifically to build this reputation over 2–4 weeks.
Fix: Do not panic. Run warmup for 14–21 days and then retest. Per Woodpecker's email warmup guide, inbox reputation takes a minimum of 2–4 weeks to develop. A day-0 inbox showing 100% spam placement is normal; a 21-day-warmed inbox showing 100% spam placement would be a real problem.
Symptom: An inbox that has been placing at 88%+ primary for 6 weeks suddenly tests at 45% primary with no obvious change to the infrastructure or content.
Cause: Sudden placement drops typically have one of three causes: a spam complaint spike from a recent campaign (check campaign analytics for an unsubscribe or complaint spike that coincides with the drop), the sending domain or IP appearing on a new blacklist (check MXToolbox), or a DNS record change that accidentally broke authentication.
Fix: Check the timeline. When did the drop occur? Compare that date with: recent campaign send dates (to check for complaint correlation), recent DNS changes, and Google Postmaster Tools for the domain. Start with the most likely cause based on timing, fix it, and retest. If no obvious cause is identifiable, running the domain through a full DNS authentication check often reveals a subtly broken record.
Instantly reviews on G2 consistently identify the deliverability test as one of the features practitioners value most for high-volume agency work, with reviewers noting that the pre-campaign testing workflow directly correlates with the platform's open rate performance.
Woodpecker's cold email benchmark study establishes that top-quartile senders with 15–20% reply rates consistently achieve 30–50% open rates, which directly implies above-80% primary inbox placement. Below-average senders with 3–5% reply rates typically have placement issues contributing to low open rates beyond just message quality.
"I run a placement test before every single campaign. It has caught problems 4 times this year — once a misconfigured DKIM on a new inbox, twice for content issues, once after our IP got flagged. Each time catching it early saved the campaign."
— Verified G2 reviewer, Instantly reviews on G2
"The first time I ran a placement test before launching instead of after launch, I caught a missing DMARC record that would have sent the entire campaign to spam. Fifteen minutes of diagnosis and fix versus an entire campaign wasted. Every cold email operator should make this mandatory."
— Verified G2 reviewer, cold email consultant, Instantly reviews on G2
| Need | Tool | Notes |
|---|---|---|
| Verified B2B contacts | Quarvio | One-time purchase, no subscription |
| Email inboxes | Inframail | Microsoft 365 inboxes, auto DNS |
| Cold email sending | Instantly | Sequences, warm-up, placement testing |
| LinkedIn outreach | Aimfox | Connection campaigns, Unibox |
| Blacklist monitoring | MXToolbox | Free domain and IP blacklist check |
| Domain reputation | Google Postmaster Tools | Gmail-specific reputation and complaint rate |
How do I run an inbox placement test in Instantly?
Navigate to the Deliverability Test feature in your Instantly account (location varies by plan tier — check main navigation, Tools, or Settings). Click Create New Test. Enter your exact campaign subject line and body copy. Select the specific sending inbox to test. Click Run Test and wait 2–5 minutes for results. Review the overall score and the per-provider breakdown. If the score is 80%+ primary inbox, proceed to launch. If below 80%, diagnose the cause before launching.
What is an inbox placement test and how does it work in Instantly?
An inbox placement test sends a copy of your email to a network of controlled seed addresses spread across Gmail, Outlook, Yahoo, and other email providers. Each seed address is monitored, and the test reports back what folder the email landed in at each provider: primary inbox, spam, or promotions tab. The results show where your email would land for real recipients using these providers, allowing you to fix delivery problems before the campaign starts.
What is a good inbox placement score in Instantly?
80% or above in the primary inbox is the minimum acceptable threshold before launching a campaign. 90%+ is excellent and indicates the infrastructure, content, and domain reputation are all healthy. Between 80–89%, you can launch but should monitor open rates closely in the first 48 hours. Below 80%, diagnose and fix before launching. Below 60% is critical and requires immediate attention to infrastructure or domain reputation.
How often should I run inbox placement tests?
Before every new campaign (mandatory). After any significant copy change (subject line, links, or body structure). After adding new sending inboxes. After any DNS or infrastructure change. After recovering from a spam complaint spike or blacklisting. On a monthly maintenance schedule for all active sending domains even without new campaigns. Per Woodpecker's cold email infrastructure guide, the 5-minute cost of a placement test is always lower than the campaign cost of discovering a placement problem after sending.
Why is my inbox placement test showing spam on Gmail but inbox on Outlook?
Gmail-specific spam placement with good Outlook placement typically points to a content or Gmail-reputation issue rather than an authentication problem (authentication problems usually affect all providers simultaneously). Check Google Postmaster Tools for the sending domain's reputation. If reputation is "low," Gmail placement will remain poor until reputation recovers. If reputation is "medium" or higher, strip HTML formatting and remove all links except one, then retest. Gmail's Promotions routing and spam classification is more sensitive to formatting and link density than Outlook's.
What does "promotions" mean in the Instantly inbox placement test?
Promotions is a Gmail-specific folder where Gmail routes emails it identifies as commercial or marketing in nature, as distinct from personal and transactional email. Emails in Gmail Promotions are not blocked, but recipients check this tab far less frequently than their primary inbox. For B2B cold email, primary inbox placement is strongly preferred over promotions placement. Promotions routing is typically caused by HTML-heavy email formatting, multiple links, commercial language, or unsubscribe footer prominence. Switching to plain text with one link usually moves placement from promotions to primary for well-authenticated sending domains.
Can an inbox placement test catch DKIM and SPF problems?
Yes. Placement tests indirectly reveal authentication problems because email providers heavily penalize emails with missing or misconfigured authentication. If your placement test shows comprehensive spam placement across all providers simultaneously, this is a strong signal of authentication failure. The test result alone does not tell you which record is missing — that requires using a DNS verification tool or the authentication report in Instantly's deliverability test results to identify the specific problem.
How long does an inbox placement test take in Instantly?
Results typically appear within 2–5 minutes after clicking Run Test. The seed network distributes and processes the test email in parallel, so more seed addresses do not significantly increase the wait time. If results have not appeared after 10 minutes, the test email may not have sent successfully — check the inbox connection status in Instantly's Email Accounts.
What should I fix first if my inbox placement test shows spam placement?
Diagnose in this order: (1) Check DNS authentication — verify SPF, DKIM, and DMARC are all correctly configured. Authentication problems cause the most severe and widespread spam placement. (2) Check domain blacklist status on MXToolbox blacklist checker. (3) Check domain reputation on Google Postmaster Tools. (4) If infrastructure is clean, isolate content as the cause by testing a stripped plain-text version. Fix in the order discovered — addressing authentication first because content fixes will not help on an unauthenticated domain.
Does the Instantly inbox placement test use real email addresses?
Instantly uses a network of seed addresses — controlled email accounts created and monitored specifically for placement testing. These are real email accounts at real providers (Gmail, Outlook, Yahoo, etc.), but they are monitored accounts used solely for testing purposes, not real prospect inboxes. The results reflect how real email providers would handle your email based on current authentication, content scoring, and domain reputation.
Should I run a placement test before every cold email campaign?
Yes, without exception. Even if the sending domain has been used successfully for weeks and the infrastructure is unchanged, new campaign copy requires a fresh test. A subject line that passes testing with one campaign does not guarantee the next campaign's subject line and body will also pass — content scoring evaluates the specific email being sent. The 5-minute investment in a placement test before every campaign is one of the highest-ROI steps in the campaign setup process.
Why does my inbox placement test pass but open rates are still low?
The placement test reflects seed network results; real-world placement may differ if: (1) your contacts use corporate email systems with additional third-party security filtering (Proofpoint, Mimecast) that classifies email more aggressively than standard Gmail; (2) the sending domain has been blocked by specific corporate email administrators; or (3) Apple Mail Privacy Protection is deflating real open rates by making it appear as though fewer opens are happening (MPP fires the tracking pixel automatically, so some provider breakdowns may look inflated). If the test shows 85%+ but open rates are below 20%, check bounce rate first — a high bounce rate (above 3%) indicates list quality is causing delivery failures that look like open rate problems.
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