Inbox Placement Test

Predict whether your emails will land in the primary inbox or the spam folder by analyzing your domain's technical sender reputation.

Evidence ASSESSED

Checked against: SPF, DKIM and DMARC alignment combined with DNSBL status

RED TEAM 0 findings BLUE TEAM control did not hold

Placement Factors

Landing in the inbox is a combination of technical setup and historical reputation:

Authentication (SPF/DKIM/DMARC): Essential for proving you are a legitimate sender. Missing records almost guarantee spam placement.
IP Reputation: If your sending server's IP is on a blacklist (RBL), your mail will be blocked or filtered.
Engagement: Recipient providers (Gmail, Outlook) track how users interact with your mails (Open rate, Mark as Spam).
Content: Avoid "spammy" keywords, excessive capitalization, and broken HTML in your email body.

Our Inbox Placement Test evaluates the factors that determine whether your mail lands in the inbox or the spam folder — authentication, alignment, reputation and infrastructure — and identifies which of them is holding you back.

What is Inbox Placement?

Inbox placement is where accepted mail actually lands. It is a different question from deliverability in the narrow sense: a message can be accepted by the receiving server, generate no bounce, and still be filed directly into the spam folder where nobody sees it.

This distinction matters because the sender receives no feedback. A rejected message produces a bounce you can act on. A message filed as spam produces nothing at all, so senders routinely believe their mail is being delivered when in practice it is not being read.

Placement is decided by the receiving provider based on authentication, sending reputation, recipient engagement and content. Each major provider weights these differently, which is why the same campaign can land in the inbox at one provider and the spam folder at another.

Where accepted mail lands, as distinct from whether it is accepted
Spam folder delivery generates no bounce and no feedback
Decided by authentication, reputation, engagement and content
Each provider weights the factors differently
Engagement signals increasingly dominate at the major providers

Why Inbox Placement Matters

Mail in the spam folder is functionally undelivered. Password resets that are not seen generate support tickets, order confirmations that are not seen generate disputes, and marketing that is not seen generates nothing at all — while the sending statistics report successful delivery throughout.

Placement problems also compound. Recipients who never see your mail never engage with it, and low engagement is itself a negative signal that worsens placement further. A reputation decline that is not addressed tends to accelerate rather than stabilise.

Spam folder mail is functionally undelivered but reported as successful
Transactional mail failures generate support load and disputes
Low engagement from poor placement worsens placement further
The decline accelerates rather than stabilising if unaddressed
Sending statistics give no warning of the problem

How This Inbox Placement Test Works

The tool evaluates the sender-side factors that drive placement decisions.

Validates the domain input against format and SSRF safety checks
Checks SPF, DKIM and DMARC configuration and alignment
Assesses blacklist status for the domain and its sending infrastructure
Verifies reverse DNS and HELO consistency
Reports which factors are likely to be limiting placement

How to Use the Inbox Placement Test

Enter your sending domain in the input field
Run the test to evaluate the placement factors
Address authentication and alignment problems first
Resolve any blacklist listings before making other changes
Monitor engagement metrics, which increasingly drive placement at major providers

Understanding Your Placement Factors

Each factor influences where mail lands:

Field / Value	Meaning
`Authentication`	Whether SPF, DKIM and DMARC are correctly configured. The baseline requirement — without it, placement problems cannot be solved by anything else.
`DMARC alignment`	Whether the authenticated domain matches your From domain. SPF and DKIM can both pass while neither aligns, which fails DMARC and harms placement.
`Blacklist status`	Whether the domain or sending IPs are listed. A listing on a widely consulted list moves mail to spam or causes outright rejection at many receivers.
`Reverse DNS`	Whether sending IPs have PTR records resolving forward to the same address. A basic requirement that causes rejection when absent.
`Sending reputation`	Built from volume consistency, complaint rates and bounce rates over time. The dominant factor once the technical basics are correct.
`Engagement`	Whether recipients open, reply and move messages out of spam. Increasingly the primary signal at Gmail and Outlook, and largely outside direct technical control.
`Content signals`	Link quality, image-to-text balance and phrasing. Real but secondary — they matter most when other signals are already marginal.

Common Problems & How to Fix Them

Work through the factors in order of weight.

Confirm DMARC alignment rather than just SPF and DKIM passing — unaligned passes fail DMARC entirely. Check blacklist status for both domain and sending IPs. Verify reverse DNS matches the HELO hostname. If all of those are correct, the issue is reputation or engagement, which take time rather than configuration to fix.

Providers weight signals differently, and each maintains its own reputation data about your sending.

Check provider-specific tools — Google Postmaster Tools and Microsoft SNDS both expose reputation data you cannot see otherwise. A problem visible only at one provider usually reflects complaint rates or engagement among that provider users specifically.

A sudden change points to a discrete event rather than gradual drift.

Check for a new blacklist listing, a compromised account sending spam, a volume spike from a campaign, or a change in sending infrastructure. A sharp increase in complaint rate from one campaign can affect placement for everything that follows.

Sending both from the same domain and IP means marketing complaint rates affect transactional placement, which is the more damaging failure.

Separate the streams: use a dedicated subdomain and sending infrastructure for transactional mail. Password resets and receipts then build their own reputation, insulated from campaign performance.

Once the technical factors are right, the remaining variables are reputation and engagement, and neither responds to configuration changes.

Improve list hygiene by removing unengaged recipients, make unsubscribing easy so people use it rather than reporting spam, and send to people who actually want the mail. Volume sent to disengaged recipients actively damages placement for everyone else.

Best Practices

Get SPF, DKIM and DMARC correct and aligned before anything else
Separate transactional and marketing mail onto different subdomains and infrastructure
Register with Google Postmaster Tools and Microsoft SNDS for provider-specific data
Remove unengaged recipients rather than continuing to mail them
Make unsubscribing easy, since a spam complaint is far more damaging
Keep sending volume consistent rather than sending in large irregular bursts
Warm up new domains and IPs gradually

Security Recommendations

Treat a sudden placement decline as a possible compromise, since a hijacked account sending spam is a common cause
Enforce DMARC so spoofed mail using your domain does not damage your reputation
Audit every third-party sender in your SPF record, as each affects your reputation
Monitor DMARC aggregate reports for unfamiliar sources sending as your domain
Secure forms and endpoints that could be abused to send arbitrary mail
Separate transactional mail infrastructure so a marketing reputation problem cannot block password resets

Frequently Asked Questions

Deliverability is whether the receiving server accepts the message. Inbox placement is where it goes afterwards. A message can be accepted with no bounce and filed straight into spam, which is reported as successful delivery.

Each provider maintains its own reputation data and weights signals differently. Gmail places particular weight on engagement among its own users. Google Postmaster Tools exposes reputation data specific to your sending that you cannot see otherwise.

No. Authentication removes reasons to reject or distrust you, but placement is then decided by reputation and engagement. Correct SPF, DKIM and DMARC are necessary rather than sufficient.

Fix authentication and alignment first, resolve any blacklist listings, ensure reverse DNS is correct, then focus on engagement — remove unengaged recipients, make unsubscribing easy, and send consistent volumes to people who want the mail.

Yes. Sending both from the same domain and infrastructure means marketing complaint rates affect password resets and receipts. A dedicated subdomain and sending infrastructure for transactional mail insulates it from campaign performance.

Sudden changes usually have discrete causes: a new blacklist listing, a compromised account sending spam, a volume spike, or a campaign that generated unusually high complaints. Gradual decline points to reputation drift instead.

Less than most senders expect. A well-authenticated sender with good reputation has considerable latitude. Content signals matter most when the other factors are already marginal, at which point they tip the decision.