Email Spam Test

Test your domain's technical configuration to see if it triggers common spam filters used by major email providers.

Evidence ASSESSED

Checked against: Local rule set scoring SPF, DKIM, DMARC and DNSBL signals

RED TEAM 0 findings BLUE TEAM control did not hold

Spam Filtering Logic

Spam filters use a scoring system to decide whether to deliver an email. Common triggers include:

Authentication Failures: Failing SPF, DKIM, or DMARC checks results in a heavy penalty.
Blacklisted IPs: If your mail server IP is on a Real-time Blackhole List (RBL), your score will be very high.
Metadata Issues: Missing PTR records, invalid HELO hostnames, or lack of proper SSL certificates.
Reputation History: A domain that has sent spam in the past will be monitored more closely.

Our Email Spam Check assesses the signals that determine whether mail from your domain reaches the inbox — authentication configuration, blacklist status, reverse DNS, and the infrastructure characteristics filters evaluate before a message is even read.

What Determines Spam Classification?

Spam filtering evaluates a message long before it considers the content. By the time the subject line is read, a substantial part of the decision has already been made from signals attached to the sending domain and IP.

Authentication comes first: does SPF authorise this server, is there a valid DKIM signature, does DMARC align, and is the policy enforced. Then reputation: is the sending IP or domain on any blocklist, what is the historical complaint rate, and how much mail has this source sent before. Then infrastructure: does the IP have reverse DNS, does it match the HELO hostname, and is the sending range associated with abuse.

Content signals — spammy phrasing, image-heavy layouts, suspicious links — matter, but they matter far less than most senders assume. A well-authenticated message from a clean IP with an established record has substantial latitude that a poorly configured sender does not.

Authentication and reputation are evaluated before content
SPF, DKIM and DMARC form the technical foundation
Blacklist status and complaint rates carry heavy weight
Reverse DNS and HELO consistency are basic requirements
Content signals matter less than sender configuration

Why Spam Signal Assessment Matters

Deliverability failures are largely silent. Mail routed to spam folders generates no bounce, no error and no notification — the message simply is not read, and the sender has no way of knowing unless they look.

Since February 2024, Google and Yahoo have required bulk senders to authenticate with SPF and DKIM, publish DMARC, and keep complaint rates below a defined threshold. Domains that do not comply see delivery failures that no amount of content improvement will fix, because the problem is configuration rather than messaging.

Spam folder delivery produces no bounce and no notification
Google and Yahoo bulk sender rules have applied since February 2024
Configuration problems cannot be fixed by improving content
A single blacklist listing can stop delivery to many receivers at once
New domains and IPs need deliberate warm-up regardless of setup quality

How This Email Spam Check Works

The tool assesses the configuration and reputation signals receivers evaluate.

Validates the domain input against format and SSRF safety checks
Retrieves and evaluates SPF, DKIM and DMARC configuration
Checks the domain and associated addresses against blocklists
Verifies reverse DNS and HELO consistency for the sending infrastructure
Combines the findings into a deliverability assessment with specific remediation

How to Use the Email Spam Check

Enter your sending domain in the input field
Run the assessment to evaluate the signals
Address authentication problems first, since they carry the most weight
Resolve any blacklist listings at their source
Re-check after each change and monitor DMARC reports for confirmation

Understanding Your Spam Signal Results

Each signal contributes differently to the filtering decision:

Field / Value	Meaning
`SPF`	Whether a valid record exists and authorises your sending servers. A missing or over-limit record removes one of the two DMARC authentication paths.
`DKIM`	Whether outgoing mail is signed and the public key is published. More robust than SPF because it survives forwarding.
`DMARC`	Whether a policy is published and enforced. Required by Google and Yahoo for bulk senders, and p=none satisfies the letter of that requirement while providing no protection.
`Blacklist status`	Whether the domain or its sending addresses appear on blocklists. A listing on a widely used list can stop delivery to a large share of receivers immediately.
`Reverse DNS`	Whether sending IPs have PTR records that resolve forward to the same address. A missing PTR causes outright rejection at many receivers.
`HELO consistency`	Whether the hostname announced at connection matches the reverse DNS and has a valid forward record. Inconsistency is treated as a spam signal.
`Domain age`	Recently registered domains face additional scrutiny regardless of configuration, which is why warm-up periods are necessary.

Common Problems & How to Fix Them

Authentication is necessary but not sufficient. Check the remaining signals in order.

Confirm the sending IP has valid reverse DNS matching the HELO hostname. Check blacklist status for both the domain and the IP. If the domain or IP is new, the issue is likely reputation rather than configuration, and a warm-up period is what resolves it.

Also check DMARC alignment — SPF and DKIM can both pass while neither aligns with your From domain, which fails DMARC entirely.

Identify why before requesting delisting, or you will simply be relisted.

Common causes are a compromised account sending spam, a misconfigured form allowing arbitrary sending, a shared IP damaged by another tenant, or list hygiene problems generating high complaint rates. Fix the cause, then use the delisting process each list publishes.

This causes outright rejection at many large receivers, not merely spam folder placement.

Reverse DNS is controlled by the IP block owner, so set it through your hosting provider control panel or by raising a ticket. Point it at a hostname on your own domain, and ensure that hostname resolves forward to the same address.

This satisfies the bulk sender requirement to have a record, but provides no protection and signals an incomplete setup.

Review your DMARC aggregate reports to confirm every legitimate sender authenticates and aligns, then move to p=quarantine and subsequently p=reject. Enforcement also enables BIMI, which is the visible reward for the work.

Filters apply extra scrutiny to recently registered domains and unfamiliar sending IPs regardless of configuration quality.

Warm up deliberately: begin with low volumes to recipients who engage, increase gradually over several weeks, and keep complaint rates low. Sending a large campaign from a new domain on day one reliably damages the reputation you are trying to build.

Best Practices

Configure SPF, DKIM and DMARC correctly before sending any volume
Set reverse DNS on every sending IP and match it to the HELO hostname
Monitor blacklist status continuously rather than discovering listings from complaints
Warm up new domains and IPs gradually
Keep complaint rates below the thresholds Google and Yahoo publish
Use DMARC aggregate reports to verify every sending source aligns
Maintain list hygiene, since engagement is itself a reputation signal

Security Recommendations

Investigate a blacklist listing as a possible compromise, since a hijacked account sending spam is a common cause
Enforce DMARC rather than leaving it at p=none, which protects your domain from being spoofed by others
Audit every third-party sender authorised in your SPF record, as each one can send as your domain
Monitor DMARC reports for unfamiliar sending sources, which reveal both shadow IT and active spoofing
Secure forms and contact endpoints against being abused to send arbitrary mail
Rotate DKIM keys periodically and remove retired selectors

Frequently Asked Questions

Most commonly a configuration problem rather than content: missing or misaligned authentication, a blacklist listing, absent reverse DNS, or a new sending domain with no established reputation. Content matters far less than senders usually assume.

No. They are necessary but not sufficient. Reputation, complaint rates, reverse DNS consistency and sending history all contribute. Correct authentication removes the reasons to reject you; it does not by itself earn the inbox.

Since February 2024, senders of more than 5,000 messages a day to their users must authenticate with SPF and DKIM, publish a DMARC record, support one-click unsubscribe, and keep spam complaint rates below 0.3 per cent.

First find and fix why you were listed — a compromised account, an abusable form, or list hygiene problems. Then follow the delisting process the list publishes. Requesting delisting without fixing the cause results in relisting.

Most large receivers check whether the connecting IP has a PTR record. An address with none resembles a compromised consumer machine, so many refuse the connection outright before the message is even offered.

Several weeks. Start with low volumes to recipients likely to engage, then increase gradually. Sending a large campaign immediately from a new domain damages the reputation you are attempting to establish.

It does, but less than sender configuration. A well-authenticated sender with a clean record has considerable latitude, while a poorly configured one is filtered regardless of how well written the message is.