--- title: "What is the right approach to fix the “550 5.7 0 Email Rejected Per SPF Policy” error code? | DuoCircle" description: "Email deliverability is one of the primary factors in deciding whether your day-to-day emails and specially curated email campaigns will land in your inboxes." image: "https://www.duocircle.com/images/og-default.png" canonical: "https://www.duocircle.com/blog/email-security/how-to-fix-550-5-7-0-email-rejected-due-to-spf-policy/" --- Quick Answer The 550 5.7.0 Email Rejected Per SPF Policy error means SPF validation failed at the receiving server, usually from one of three causes. Fix it three ways. First, validate the SPF record with an online lookup tool to catch syntax errors: typos, extra commas or spaces, incorrect mechanism use, and uppercase letters. Second, check MX records: a mismatch between the sender's domain and the MX records can trigger rejection, so confirm MX points to the correct mail server. Third, list every third-party sender in the SPF record. Tools that send on your behalf (marketing platforms, CRMs, ticketing) need their sending sources in the include or ip4 mechanisms, or their mail will fail SPF. If the SPF record exceeds the 10 DNS lookup limit (common with multiple vendors and nested includes), use SPF flattening to resolve includes to direct IPs and stay under the limit. Share [ ](https://www.linkedin.com/sharing/share-offsite/?url=undefined%2Fblog%2Femail-security%2Fhow-to-fix-550-5-7-0-email-rejected-due-to-spf-policy%2F "Share on LinkedIn") [ ](https://twitter.com/intent/tweet?text=What%20is%20the%20right%20approach%20to%20fix%20the%20%E2%80%9C550%205.7%200%20Email%20Rejected%20Per%20SPF%20Policy%E2%80%9D%20error%20code%3F&url=undefined%2Fblog%2Femail-security%2Fhow-to-fix-550-5-7-0-email-rejected-due-to-spf-policy%2F "Share on X/Twitter") [ ](https://www.facebook.com/sharer/sharer.php?u=undefined%2Fblog%2Femail-security%2Fhow-to-fix-550-5-7-0-email-rejected-due-to-spf-policy%2F "Share on Facebook") [ ](https://reddit.com/submit?url=undefined%2Fblog%2Femail-security%2Fhow-to-fix-550-5-7-0-email-rejected-due-to-spf-policy%2F&title=What%20is%20the%20right%20approach%20to%20fix%20the%20%E2%80%9C550%205.7%200%20Email%20Rejected%20Per%20SPF%20Policy%E2%80%9D%20error%20code%3F "Share on Reddit") [ ](mailto:?subject=What%20is%20the%20right%20approach%20to%20fix%20the%20%E2%80%9C550%205.7%200%20Email%20Rejected%20Per%20SPF%20Policy%E2%80%9D%20error%20code%3F&body=Check out this article: undefined%2Fblog%2Femail-security%2Fhow-to-fix-550-5-7-0-email-rejected-due-to-spf-policy%2F "Share via Email") ![Email Rejected](https://media.mailhop.org/duocircle/images/2024/10/spf-record-8415.jpg) Email deliverability is one of the primary factors in deciding whether your **day-to-day emails** and specially curated [email campaigns](https://www.activecampaign.com/glossary/email-campaign) will land in your inboxes or get marked as spam. There could be several reasons your [email deliverability](/a-guide-on-email-deliverability) is low, including the “550 5.7 0 Email Rejected Per SPF Policy” error code. When your [SPF verification fails](/content/spf-validation-failed), this error is triggered. It indicates that some opportunities were missed and that there were **operational inconsistencies**. _It also points to strained relationships. Let’s understand it better_. ## What is the “550 5.7 0 Email Rejected Per SPF Policy” error? “550 5.7 0 Email Rejected Per SPF Policy” error occurs due to misconfigurations in your [email server](https://www.one.com/en/email/what-is-an-email-server), which happens due to invalid or incomplete SPF records, the presence of [anti-spam tools](/spam-filtering/stop-spam-in-its-tracks-with-superior-anti-spam-tools/), and [malware injection attacks](https://www.darkreading.com/vulnerabilities-threats/attacks-on-bytecode-interpreters-conceal-malicious-injection-activity). Whenever emails travel through **multiple servers**, SPF breaks and returns this error message. [![anti-spam tools](https://media.mailhop.org/duocircle/images/2024/10/spf-record-check-9745.jpg)](https://media.mailhop.org/duocircle/images/2024/10/spf-record-check-9745.jpg) But thankfully, it’s in your hands to fix this error and **improve your email deliverability** for better results and efficacy. ## How can you troubleshoot the “550 5.7 0 Email Rejected Per SPF Policy” error? There are mainly three things you can do- ### Rectify your SPF record Invalid [SPF records](/content/spf-records) will receive this error code. So, regularly run your SPF record through a credible online SPF record lookup tool that will bring the **inconsistencies and errors** to the surface so that you can correct them. _Some of the common errors that you can expect are spelling errors, extra commas and spaces, incorrect use of syntax, and the use of uppercase letters_. ### Double-check your MX (Mail Exchange) record _Another cause of the “550 5.7.0 email rejected per SPF policy” error could be incorrect MX records_. If the [SMTP server](https://www.brevo.com/blog/what-is-smtp-server/) identifies a mismatch between the sender’s domain and the domain listed in the [MX records](https://www.digicert.com/faq/dns/what-is-an-mx-record), it will reject the email. To resolve this issue, ensure that your **domain’s MX records** are correctly configured to point to the appropriate server. ### Don’t miss adding third-party vendors’ sending sources If you rely on [third-party vendors](https://www.upguard.com/blog/third-party-vendor) to send emails on your behalf, you need to add their sending sources to your SPF record; otherwise, emails sent by them will not **pass the authentication checks** and land in the [spam folders](https://cybernews.com/news/microsofts-breach-notification-emails-end-up-in-spam-folder/) or [bounce back](https://snov.io/blog/email-bounce-back/) (depending on what mechanism you have set in your SPF record). This is an important step, yet many domain owners aren’t aware of it or just ignore it. [![third-party vendor](https://media.mailhop.org/duocircle/images/2024/10/sender-policy-framework-4.jpg)](https://media.mailhop.org/duocircle/images/2024/10/sender-policy-framework-4.jpg) ## Final words If your organization’s [email infrastructure](https://www.voilanorbert.com/blog/email-infrastructure/) is complex and involves **multiple dynamic IPs**, there is a high chance your record will exceed the maximum [DNS lookup limit](https://developers.cloudflare.com/dmarc-management/dns-lookup-limits/) of 10\. _If that’s the case with you, too, consider using an automatic SPF flattening tool_. We at [DuoCircle](/) take a holistic approach to [email authentication](/resources/email-authentication). If you are interested in **securing your domain** using SPF, [DKIM](/resources/what-is-dkim), and [DMARC](/resources/what-is-dmarc), please let us help you. [Contact us](/contact) to talk about it. ## Topics DKIMDMARCspfSPF record ![Brad Slavin](https://media.mailhop.org/dmarcreport/images/team/brad-slavin.jpg) Brad Slavin General Manager General Manager at DuoCircle. Product strategy and commercial lead across the email security portfolio. ## Secure your email infrastructure Protect, authenticate, and deliver. Contact our team to find the right solution. [Contact Sales](/contact/) [Explore Products](/products/) Share this article [ ](https://www.linkedin.com/sharing/share-offsite/?url=https%3A%2F%2Fwww.duocircle.com%2Fblog%2Femail-security%2Fhow-to-fix-550-5-7-0-email-rejected-due-to-spf-policy%2F) [ ](https://twitter.com/intent/tweet?text=What%20is%20the%20right%20approach%20to%20fix%20the%20%E2%80%9C550%205.7%200%20Email%20Rejected%20Per%20SPF%20Policy%E2%80%9D%20error%20code%3F&url=https%3A%2F%2Fwww.duocircle.com%2Fblog%2Femail-security%2Fhow-to-fix-550-5-7-0-email-rejected-due-to-spf-policy%2F) [ ](https://www.facebook.com/sharer/sharer.php?u=https%3A%2F%2Fwww.duocircle.com%2Fblog%2Femail-security%2Fhow-to-fix-550-5-7-0-email-rejected-due-to-spf-policy%2F) Copy Related Articles - [ ![security model for emails](https://media.mailhop.org/duocircle/images/2024/12/spf-permerror-3095.jpg) Building a zero-trust security model for emails Email Security ](/blog/email-security/building-a-zero-trust-security-model-for-emails/) - [ ![email authentication](https://media.mailhop.org/duocircle/images/2025/11/hosted-email-server-4501.jpg) How email authentication helps you prove sender identity under ISO 27001 Email Security ](/blog/email-security/how-email-authentication-helps-verify-sender-identity-for-iso-27001/) - [ ![enhance email security and deliverability](https://media.mailhop.org/duocircle/images/2025/03/smtp-providers-8732.jpg) How do you achieve SPF alignment to enhance email security and deliverability? Email Security ](/blog/email-security/how-spf-alignment-improves-email-security-and-deliverability/) - [ ![protect every email](https://media.mailhop.org/duocircle/images/2025/06/Office-365-migration-8976.jpg) How SPF, DKIM, and DMARC quietly protect every email you send? Email Security ](/blog/email-security/how-spf-dkim-dmarc-protect-every-email-you-send-securely/) ## Related Articles [ Email Security 6m Building a zero-trust security model for emails Dec 11, 2024 ](/blog/email-security/building-a-zero-trust-security-model-for-emails/)[ Email Security 7m How email authentication helps you prove sender identity under ISO 27001 Nov 18, 2025 ](/blog/email-security/how-email-authentication-helps-verify-sender-identity-for-iso-27001/)[ Email Security 6m How do you achieve SPF alignment to enhance email security and deliverability? Mar 25, 2025 ](/blog/email-security/how-spf-alignment-improves-email-security-and-deliverability/)[ Email Security 3m How SPF, DKIM, and DMARC quietly protect every email you send? Jun 13, 2025 ](/blog/email-security/how-spf-dkim-dmarc-protect-every-email-you-send-securely/) ```json {"@context":"https://schema.org","@type":"Organization","name":"DuoCircle LLC","url":"https://www.duocircle.com","logo":{"@type":"ImageObject","url":"https://www.duocircle.com/images/duocircle-logo.png"},"description":"DuoCircle is a portfolio of specialized email products covering protection, authentication, delivery, and routing. We deliver about 90% of category-leader capability at roughly half the price, backed by experts who own the outcome. 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