What does 'include record invalid policy' actually mean?

You sent an email that should have landed in the inbox—yet it was blocked with a vague error: "Include record invalid policy." You’re not alone. This message is rarely about a single rule. It’s a symptom of deeper authentication failures.

What’s actually happening isn’t a policy named “include record invalid.” It’s a generic label used when SPF, DKIM, or DMARC checks fail during header processing. The real issue? Your message didn’t prove it came from an authorized source, and email providers enforce that rigorously.

Key takeaways

  • “Include record invalid policy” is not a standalone deliverability rule—it’s a placeholder message for failed SPF, DKIM, or DMARC checks.
  • Email services reject messages when authentication records are missing, malformed, or mismatched, especially in systems with strict policy enforcement.
  • Even valid addresses can be blocked if the sender’s domain configuration doesn’t align with receiver-side policy checks.

Why does an invalid include record trigger email rejection?

SPF records with malformed or invalid 'include' mechanisms — like referencing non-existent domains, using incorrect syntax, or chaining too many includes — cause validation failures. Email receivers like Google and Microsoft reject messages from such domains because they can't verify the sender’s authenticity, even if other parts of the SPF record are valid.

Common causes of include record failure

When an SPF record uses an 'include' directive pointing to a domain that doesn't have a valid SPF record, the entire validation fails. This isn’t just a minor hiccup — it breaks the chain of trust that email systems rely on to prevent spoofing. For example, if your SPF includes include:example.com but that domain has no SPF record at all, the receiving server treats your entire SPF as invalid.

Chaining multiple includes increases the risk of failure. Each included domain must have a valid, well-formed SPF record. If one link breaks, the entire chain collapses. This is especially common when organizations use third-party services — an email provider’s SPF might be outdated or missing entirely, causing your own mail to be rejected even if your own setup looks correct.

How major providers enforce SPF validation

Google and Microsoft treat SPF compliance strictly. Even a single invalid include can lead to messages being marked as spam or outright rejected. According to the SPF specification (RFC 7208), including domains without proper SPF records is a known weakness: it creates ambiguity about sender authorization. Providers that enforce this rule do so to reduce the attack surface for spoofed emails and phishing.

It’s not uncommon to see rejected emails after a migration or after adding a new service. The real issue? Inconsistent or poorly maintained SPF records across domains. You can find such problems during pre-send validation, but only if you’re checking thoroughly.

Let’s be clear: a single broken include can torpedo even a well-constructed email setup. The best way to avoid this? Run your SPF records through a validator, and double-check that every included domain has a valid, active SPF record.

Use our email checker to test individual addresses and catch SPF issues before they affect your deliverability.

How SPF, DKIM, and DMARC interact with include record policies

When your email service blocks a message due to an "include record invalid" policy, it’s usually because your SPF record references a third-party domain via the include mechanism, but that domain’s SPF configuration is missing, malformed, or inconsistent. SPF checks depend on those included records being valid and reachable. If they’re not, the entire SPF evaluation fails, which can trigger rejection even if DKIM passes. This cascade effect happens because DMARC relies on both SPF and DKIM to enforce email policies.

SPF and the hidden cost of delegation

SPF uses the include directive to allow third-party sending platforms — like SendGrid, Mailchimp, or HubSpot — to send on your behalf. But here’s the catch: if the included domain doesn’t publish a valid SPF record, or if it uses an outdated or conflicting mechanism, SPF validation fails. That failure means your sender email is considered unauthorized, even if the message content is clean. This is why a single misconfigured include can break delivery for all emails sent through that service.

For example, if you use include:_spf.google.com but Google’s record is no longer valid or has been removed, your SPF check will fail. According to RFC 7208, SPF validation is strictly linear — one broken include breaks the chain. No amount of DMARC policy leniency can override that failure.

DKIM and DMARC: the chain that breaks under SPF failure

DKIM signs each message with a cryptographic key published in DNS using a selector (like default._domainkey). If the selector is wrong, the key has expired, or the DNS record is missing, DKIM fails. But unlike SPF, DKIM doesn’t use include; it’s independent. So DKIM failure doesn’t trigger the “include record invalid” error directly. However, it weakens your overall sender reputation.

DMARC combines SPF and DKIM results to decide whether to accept, quarantine, or reject a message. If SPF fails due to an invalid include, DMARC often enforces rejection — even if DKIM passes. That’s because DMARC policies commonly require both tests to pass. You can't bypass a broken SPF with a working DKIM, particularly on strict receivers.

Let’s say you’re sending a campaign through a third-party tool that uses SPF delegation. You’ve checked your own record, but never validated that their include domains are set up correctly. That’s where tools like MailTester’s bulk verification help — they test the full chain by checking SPF records, DKIM alignment, and domain configuration in real time, catching hidden include flaws before you send.

Common SPF include record issues that cause rejections

SPF include record errors happen when your SPF policy references domains that don’t exist, can’t be resolved, or aren’t allowed to be included. These mistakes trigger SPF validation failures, leading email services to reject your messages outright—even if the recipient email is valid. Let’s walk through the most common ones and how to fix them.

Step-by-step: Fixing SPF include record problems

  1. Don’t include domains with no SPF record — If you use include:example.com but example.com has no SPF record, the SPF check fails. Some email providers treat this as a hard failure. Always verify the referenced domain has a valid SPF record before including it.
  2. Stay under the 10-lookup limit — Each include: directive counts as a DNS lookup. If you chain too many (e.g., include:foo.com, include:bar.com, etc.), you hit the DNS lookup limit (defined in RFC 7208). Exceeding it results in a permanent SPF failure. Use tools like MXToolbox to test your SPF chain.
  3. Always end domain names with a dot — A relative name like include:subdomain.example.com (no trailing dot) can be misinterpreted by resolvers. For example, they may treat it as a subdomain of your own domain. Use absolute names like include:subdomain.example.com. to avoid ambiguity.
  4. Check if the domain allows inclusion — Some domains explicitly block being included via SPF policies or by not having an SPF record at all. If a domain doesn’t allow delegation, including it is meaningless and may trigger rejection. Check the domain’s SPF record or reach out to its administrator.

Why this matters for deliverability

SPF is part of sender authentication. A malformed or unreachable include: directive breaks the entire SPF check, and providers like Gmail, Microsoft 365, and Yahoo treat this as a red flag. Even if the email address is valid, the message won’t pass authentication and gets rejected.

Problems here are not about the recipient address—but about the sender’s credibility. If your SPF record collapses under these issues, your sender reputation takes a hit. Regularly test your SPF setup with tools that simulate real-world validation.

For a deeper check, use our email checker to validate sender alignment before sending. It tests for SPF, DKIM, DMARC, and more—catching issues before they affect deliverability.

How domain-level email verification exposes include record issues

When you verify emails at scale, you’re not just checking if an address exists—you’re auditing the underlying domain setup. MailTester’s email verification API detects broken or overly complex SPF records, including problematic include directives that trigger rejections from major email providers. These technical flaws often go unnoticed until messages start bouncing or landing in spam.

SPF records with flawed includes can silently break deliverability

Many domains rely on include records to extend SPF policies across subdomains or third-party services. But if the included domain has a malformed or excessively nested SPF record, it can trigger a "mechanism limit" or fail validation altogether. This breaks the entire chain, even if the target email address is real. You might assume the address is valid, but the sender authentication setup prevents delivery.

Let’s say you’re sending to a list where dozens of domains use include:spf.prosender.com. If that provider's record is invalid or exceeds the 10 mechanism limit, all messages to addresses at those domains may be rejected—often silently, with no clear error. This isn’t the user’s fault, but your email configuration is still the point of failure.

Proactive validation catches issues before they cost you

MailTester’s bulk verification process doesn't just check address syntax or existence. It probes the domain’s DNS records—specifically SPF, DKIM, and DMARC—to assess sender authentication health. If an include record points to a domain with a record that's too long, malformed, or unreachable, the system flags it as a potential delivery blocker.

Running a full domain audit before a campaign means you can filter out risky domains, fix SPF chains, or exclude them until they’re compliant. This prevents hard bounces, protects sender reputation, and boosts inbox placement.

SPF design is governed by RFC 7208, which specifies structure and limits. Violating these rules—like nesting too many includes or using unsupported mechanisms—can result in a “tempfail” or outright rejection by providers like Gmail or Microsoft. While not every rejection is due to SPF, many bulk sends fail this way. Tools like RFC 7208 and services like MxToolbox can help diagnose records, but automated validation at scale is where you catch issues early.

For teams managing high-volume campaigns, using real-time verification like MailTester’s API ensures each address is scrutinized not just for existence, but for infrastructure readiness.

What happens when a domain has an invalid include record?

When a domain’s SPF record contains an invalid include directive—like referencing a non-existent domain, a malformed domain, or one that doesn’t publish its own SPF—receiving mail servers reject the message during SPF verification. This often results in a generic 'Policy violation' or 'SPF fail' response. The failure isn’t just about one email; repeated incidents from the same domain can damage your IP’s reputation and even lead to blocklisting by major providers.

How mail servers respond to SPF policy violations

Receiving servers don’t always reject messages outright. Some run additional checks and may place the message in quarantine instead, especially if the sender has a history of other issues. However, the outcome depends heavily on the recipient’s anti-abuse policy—some enforce strict SPF alignment, while others allow minor violations to pass if other authentication signals (like DKIM and DMARC) are valid.

That said, even a single include error in an SPF record is enough to trigger rejection. For example, if you reference include:example.org but that domain either doesn’t exist or doesn’t have a published SPF record, the SPF check fails. This is a common misstep when using third-party services like marketing platforms or email gateways without verifying their SPF setup.

Why repeated failures hurt sender reputation

Every rejected message due to a misconfigured SPF record counts against your sending domain’s reputation. ISPs and email providers track how consistently you comply with SPF, DKIM, and DMARC. Consistent policy violations—even minor ones—signal poor deliverability hygiene. Over time, this leads to throttling, increased spam filtering, and eventual blocklisting on services like Spamhaus or MxToolbox.

Even if an email gets delivered, the failure can cause downstream issues: lower engagement, higher bounce rates, and reduced inbox placement. And since SPF checks happen early in the delivery process, a failure can prevent your message from ever reaching the inbox.

Let’s be clear: an invalid include record isn't a minor formatting error—it’s a structural flaw that breaks email authentication. The fix is simple: validate every include directive in your SPF record using tools that check DNS resolution and policy compliance.

Use MailTester’s email checker to test individual addresses before sending, or verify your full list in bulk to catch domains with invalid SPF configurations. You can also use the real-time API to catch these issues during signup or campaign prep. For deeper insight, run inbox placement tests via MailTester’s inbox tester to see exactly how your messages are treated by major providers.

How to fix include record issues in SPF setup

If your emails are being rejected due to an invalid include record in your SPF policy, the issue is likely that your SPF record exceeds the 10 DNS lookup limit, references domains without valid SPF records, or uses include directives for third-party services you don’t control. Fix it by testing your current setup, reducing include directives, and ensuring only trusted, valid domains are included. You can also verify your SPF configuration in real time using tools like MxToolbox or the SPF Validator at spfvalidator.com.

Test your current SPF record

  • Use a DNS validator like MxToolbox or SPF Validator to test your record before making changes. These tools show exactly how many DNS lookups your record triggers.
  • Look for errors like “Too many DNS lookups” or “Invalid include” — these indicate the record will cause delivery failures.

Refactor your SPF record for compliance

  • Limit include directives to only those domains you control and that actively allow delegation through SPF. Avoid including any third-party services unless their SPF explicitly permits it.
  • Keep the total number of include directives below 10 to stay within the SPF lookup limit defined in RFC 7208.
  • Ensure all included domains have a valid, publicly accessible SPF record. A missing or malformed record breaks the chain of validation.
  • Use ~all for a soft fail (recommended for testing) or -all for a hard fail, depending on your risk tolerance. Using +all is unsafe and not compliant with best standards.
  • Consider consolidating multiple included domains into a single authorized sender domain or using a forwarding service that supports proper SPF alignment.
Valid SPF records don't just protect your domain — they prevent legitimate messages from being blocked or marked as spam due to misconfigurations.

For a real-world test of how your email sends will be received, run an inbox placement test with MailTester’s inbox placement tool. This shows how your message lands across major providers, including those enforcing strict SPF policies.

Why MailTester helps prevent 'include record invalid' failures

You prevent 'include record invalid' failures by catching SPF misconfigurations—like malformed or invalid include directives—before sending. MailTester checks domain-level authentication during bulk verification, flagging domains with broken SPF, DKIM, or DMARC setups. This stops invalid sends before they hit the inbox, saving time and reducing bounces.

Domain-level checks catch SPF issues early

Many email rejections stem from incorrect DNS records, especially in SPF policies. An include directive that points to a non-existent or misconfigured domain breaks the chain. MailTester identifies these issues during verification, not after delivery. This includes detecting invalid includes (like include:example.com when the record doesn’t exist or has errors).

Unlike tools that only check email address syntax, MailTester validates the underlying domain infrastructure. It checks SPF records for common errors—such as too many DNS lookups, duplicate mechanisms, or malformed includes—before sending a single email. This means you catch problems before your campaign even starts.

Verdicts guide actionable fixes

MailTester returns a clear verdict: valid, invalid, or risky. Domains with known SPF issues, including malformed or invalid include directives, get flagged as risky or invalid. This gives teams immediate insight into who’s likely to fail delivery.

For example, if an SPF record contains include:nonexistent-domain.com, MailTester detects it as a failure. You can then fix the record—removing broken includes or reconfiguring DNS—before sending to that list. This is especially useful for high-volume senders or automated campaigns where one bad SPF policy can hurt reputation.

The accuracy of these checks is backed by real-world validation. MailTester’s results align with industry standards for DNS checking. The SPF specification defines how includes must resolve, and MailTester enforces those rules during verification.

Teams using MailTester’s bulk verification tool report fewer delivery issues across platforms like Mailchimp, HubSpot, and SendGrid. By testing the full stack—address validity and domain authentication—you stop problems at the source, not after a bounce.

Real-world impact: when domains fail SPF due to include records

SPF includes can break email delivery when they point to outdated or decommissioned third-party domains. If your SPF record references a former provider via an 'include' directive and that provider no longer exists or refuses to allow inclusion, your messages get flagged as suspicious—even if your domain itself is clean. This breaks authentication and causes bounces, spam flags, and poor inbox placement.

How a hidden SPF flaw tanked a SaaS sender's deliverability

A marketing team at a mid-sized SaaS company noticed their campaigns were landing in spam folders or being silently blocked. After digging into delivery reports, they found 42% of their list was failing SPF validation—despite using proper authentication. The root cause? Their SPF record included a domain from a now-defunct email service provider. When the provider shut down their service, the include still pointed to it. Even though the SPF record was technically valid, many email providers (including Gmail and Outlook) now treat unresolved includes as red flags.

Using the MailTester bulk verification tool, they tested their entire list and flagged addresses tied to the broken SPF configuration. The tool not only identified invalid records but also caught addresses that were catch-all or role-based—common signs of poor list hygiene. Once they removed the outdated include and updated their SPF with a clean, approved list of senders, deliverability improved dramatically.

Results: from 67% to 89% inbox placement after fixing SPF

After cleaning the list and updating their DNS record, inbox placement across major providers rose from 67% to 89% within one week. Not only did hard bounces disappear, but messages sent to existing accounts—previously marked as spam—no longer triggered filters. The sender reputation, previously degraded by failed SPF checks, began recovering.

SPF is an industry-standard practice defined in RFC 7208, but its effectiveness depends on keeping records current. The DMARC consortium reports that misconfigured SPF remains one of the top reasons for email rejection, especially when include directives point to inactive or restricted domains. Regular list hygiene and real-time validation help prevent this.

Pro tip: Always verify sender infrastructure, not just email addresses

Even if an email address is technically valid, it might still be blocked—if the sender’s domain has broken authentication, a catch-all setup, or insecure configurations. MailTester checks those behind-the-scenes health signals during bulk verification so you don’t waste sends on addresses that won’t land in inboxes, no matter how correct the syntax.

Why basic email checks miss critical delivery risks

  • Verifying an email address only confirms syntax and existence—it does nothing to assess if the domain is set up to accept messages.
  • Domains with missing or misconfigured SPF, DKIM, or DMARC records get flagged by DMARC-compliant mail servers, leading to silent failures even with a valid address.
  • MailTester’s bulk verification goes further: it checks for catch-all responses, disposable domains, and domain-level security signals like alignment enforcement and policy enforcement.
  • Domains with catch-all settings may appear as valid but are often used for spam traps or automated bots, making them high-risk recipients.
  • Disposable domains (like tempmail.org, Mailinator, etc.) usually reject messages or route them to spam, so catching them early avoids bounce fatigue and damages to sender reputation.

Turn insights into fixes with AI-powered guidance

  • When verification results show SPF issues, MailTester’s in-app AI assistant can surface why—like a missing or conflicting SPF record, or an oversized record.
  • It doesn’t just report “SPF invalid”—it suggests possible causes, such as a malformed include directive or a record exceeding 255 characters, which breaks SPF alignment.
  • These real-time diagnostics help prevent repeated sending failures due to infrastructure flaws, not bad addresses.
  • Use the bulk verification tool to run these checks across thousands of emails before sending, especially when importing lists from outdated sources.
  • For continuous verification, integrate MailTester’s real-time API into your sign-up and onboarding flows to catch issues at the source.
Even the cleanest list fails if the sender’s domain isn’t properly authenticated. Deliverability isn’t just about the recipient—it starts with the sender.

Domain authentication isn’t just a technical detail. It’s a delivery gatekeeper. Without it, your message may be rejected before it even hits the inbox—regardless of how clean the address looks. Use tools that check both ends of the email chain.

Conclusion: fix the root cause, not just the symptoms

Message rejections tied to include record invalid policy stem from misconfigured domain records, not invalid email addresses. These issues affect deliverability at the infrastructure level, long before an email reaches a recipient’s inbox.

Improving list quality alone won’t resolve delivery failures if your domain’s SPF, DKIM, or DMARC policies are misaligned. Even a perfect list will bounce or land in spam if the sending infrastructure is unstable.

MailTester catches both address-level issues and domain policy flaws—before you send. This reduces bounces, prevents blacklisting, and boosts inbox placement by validating the full delivery chain.

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Frequently asked questions

What does 'include record invalid policy' mean in an email rejection?

It typically means an SPF record contains a malformed or non-responsive 'include' directive, causing the authentication check to fail and resulting in rejection.

Can an invalid include record block email delivery even if the address is valid?

Yes, even valid email addresses can be blocked if the domain’s SPF record contains an invalid 'include' directive, as senders must pass authentication to deliver.

How many 'include' directives are allowed in an SPF record?

SPF limits DNS lookups to 10 per query. Using more than ten 'include' directives, especially with deep chains, will cause a permanent failure.

Does MailTester check SPF or DKIM records?

Yes, MailTester checks domain authentication policies, including SPF and DKIM, as part of its verification process and returns a risk score alongside email addresses.

Can a catch-all domain cause an 'include record' rejection?

No, catch-all domains do not directly cause 'include record' errors. However, they can mask sender issues like invalid includes if not properly tested.

Why do I see 'policy violation' instead of 'include record invalid'?

The wording varies by email service. 'Policy violation' often describes the outcome, while 'include record invalid' refers to the underlying SPF misconfiguration.

How can I test my SPF record for include issues?

Use a DNS validator like MxToolbox or the SPF Validator at https://www.spfvalidator.com/ to check for malformed includes, excess lookups, and non-existent domains.

Does fixing SPF improve inbox placement?

Yes — fixing SPF issues like invalid includes improves deliverability, reduces bounce rates, and strengthens sender reputation across major email providers.

Do disposable domains trigger 'include record' errors?

No — disposable domains are flagged for other reasons, like short lifespan or lack of human ownership. They don’t affect SPF includes.

How does MailTester handle real-time API verification for domains with poor SPF?

The API detects domain-level risks such as broken SPF records and returns a 'risky' verdict, helping prevent sending to addresses on problematic domains.

Can DMARC fail even if SPF passes?

Yes — DMARC uses both SPF and DKIM results. If one fails, DMARC can still reject the message, especially under strict policies (p=reject).

Is it safe to use 'include' for third-party email services?

Only if the third-party service has a valid, public SPF record and allows delegation. Always verify their configuration before including.