What does it mean when SPF is not aligned in a DMARC report and how does it affect deliverability?
Matthew Whittaker
Co-founder & CTO, Suped
Published 18 Jul 2025
Updated 19 Aug 2025
8 min read
Understanding a DMARC report can sometimes feel like decoding a secret language, especially when you encounter phrases like "SPF not aligned." Many senders mistakenly believe this means their SPF record is completely broken or that their emails will automatically land in the spam folder. However, the reality is more nuanced.
DMARC (Domain-based Message Authentication, Reporting, and Conformance) is an email authentication protocol that builds upon two earlier standards: SPF (Sender Policy Framework) and DKIM (DomainKeys Identified Mail). Its primary goal is to protect your domain from impersonation and phishing by telling receiving mail servers how to handle emails that claim to be from your domain but fail authentication checks.
When your DMARC report shows SPF as "not aligned," it doesn't necessarily mean your email failed authentication or won't be delivered. Instead, it points to a specific relationship between the domains used in your email headers. Let's delve into what this means and how it truly impacts your email deliverability.
SPF alignment is a critical component of DMARC that checks if the domain in the "From" header (the one your recipients see) matches a domain that passed the SPF authentication check. Specifically, DMARC requires alignment between the RFC5322.From domain (the display-from address) and the RFC5321.MailFrom domain (also known as the Return-Path or envelope sender). If these two domains are the same, SPF is considered aligned. If they are different, SPF is not aligned, even if the SPF record itself correctly authorized the sending IP address.
You can configure SPF alignment in two modes: "relaxed" or "strict". Relaxed alignment allows a subdomain of the organizational domain to pass, for example, if bounce.example.com is the MailFrom domain and example.com is the From header domain, it would align under relaxed mode. Strict alignment, on the other hand, requires an exact match between the two domains. For more details on this, you can review how relaxed domain alignment works.
The key takeaway here is that an SPF record can be perfectly valid and correctly authorize an IP to send on behalf of your domain, but still not satisfy the DMARC alignment requirement. This is a common point of confusion, as many believe that a passing SPF record automatically means DMARC compliance for SPF. However, DMARC explicitly checks for this domain correlation, which is separate from the SPF authentication check itself.
Scenario
SPF Authentication
SPF Alignment
DMARC Outcome (SPF only)
MailFrom and From domains match, IP authorized
Pass
Aligned
Pass
MailFrom is subdomain of From, IP authorized (relaxed alignment)
Pass
Aligned (relaxed)
Pass
MailFrom and From domains differ, IP authorized (no alignment)
Pass
Not aligned
Fail
MailFrom and From domains match, IP not authorized
Fail
Not aligned
Fail
Why SPF misalignment occurs
The most common reason for SPF misalignment is when you use a third-party email service provider (ESP). Many ESPs, for operational reasons, will use their own domain or a subdomain of yours for the Return-Path (MailFrom) address. This domain is where bounces and other mail system messages are sent. If this Return-Path domain doesn't match your "From" header domain (the domain your recipients see), SPF will pass but SPF alignment will fail under DMARC.
Another frequent culprit for SPF misalignment is email forwarding. When an email is forwarded, the MailFrom address often changes to that of the forwarding server. This breaks the direct alignment with your original "From" domain, even if the SPF record was valid at the initial sending point. This is a common issue that can lead to unexpected DMARC failures, as highlighted by Postmark's article on email forwarding.
Scenario: SPF misalignment due to ESP
Your ESP sends emails using their own domain (e.g., bounce.getresponse.com) for the Return-Path, while your visible From: header is your domain (e.g., yourdomain.com). SPF passes because the ESP's domain is correctly authorized by their SPF record, but it doesn't align with yourdomain.com.
Impact on DMARC
In this scenario, SPF authentication passes, but SPF alignment fails for DMARC. If your DKIM signature is correctly aligned, your email will still pass DMARC. However, if DKIM also fails, the email will fail DMARC and be subject to your DMARC policy (quarantine, reject, or none). This highlights why DMARC authentication can fail even if SPF and DKIM pass.
Impact on deliverability and sender reputation
The good news is that SPF misalignment does not automatically doom your email to the spam folder, especially if DKIM is properly configured and aligned. DMARC requires at least one of SPF or DKIM to pass and align for the message to achieve DMARC compliance. So, if your SPF is unaligned but your DKIM is aligned, your email will still pass DMARC and generally be delivered successfully. This is a common setup, particularly with many ESPs. Both Google and Yahoo emphasize the need for at least one of these to pass and align.
However, if both SPF and DKIM fail to align (or fail authentication altogether), then your email will fail DMARC. When DMARC fails, the recipient mail server will apply the policy specified in your DMARC record. This could be p=none (monitor only), p=quarantine (send to spam/junk), or p=reject (block the email entirely). This is where SPF misalignment can significantly impact your email deliverability.
Consistent SPF misalignment, especially if not compensated by DKIM alignment, can erode your sender reputation over time. Mailbox providers track authentication results, and a pattern of DMARC failures, even with a policy of p=none, can signal poor configuration or even malicious intent. This can lead to increased spam folder placement or outright rejection of your legitimate emails, regardless of the content. You can read more about the impact of temporary SPF alignment failures.
The true impact of SPF misalignment
SPF misalignment itself might not directly cause deliverability issues if your DKIM is perfectly aligned and passes DMARC. However, it signifies a weaker authentication posture. If your DKIM ever breaks (e.g., due to content modifications or forwarding), your emails will then fail DMARC. This is why having both aligned offers greater resilience and better long-term deliverability.
Resolving SPF misalignment issues
To achieve full SPF alignment, you need to ensure that the domain in your Return-Path (envelope sender) domain either exactly matches or is a subdomain of your From header domain. Many ESPs offer options for custom bounce domains or dedicated sending domains that can help achieve this alignment. If your ESP does not support custom Return-Path domains, achieving SPF alignment with them might be challenging or impossible, making DKIM alignment even more crucial. You can find out more about why SPF alignment might be inconsistent.
Given that SPF can be vulnerable to forwarding and often relies on ESP configuration, maintaining robust DKIM authentication is paramount. DKIM attaches a digital signature to your email's headers, which is then verified by the recipient server. As long as the DKIM signature is valid and the signing domain aligns with your "From" header domain, your email will pass DMARC, even if SPF alignment fails. This dual authentication approach provides redundancy, making your email more resilient against authentication failures.
Regularly monitoring your DMARC aggregate reports is key to understanding your email ecosystem's authentication performance. These reports provide invaluable insights into SPF and DKIM authentication results, including alignment issues, and help you identify legitimate sending sources that might not be correctly authenticated. This information empowers you to make informed decisions and troubleshoot problems proactively. Use a guide to understanding DMARC reports to help.
Best practices for DMARC alignment
Align both SPF and DKIM: Strive for alignment on both protocols for maximum resilience, even if only one is strictly required by DMARC. This redundancy protects against single points of failure, like forwarding breaking SPF.
Use custom Return-Path domains: If your ESP offers it, configure a custom Return-Path (MailFrom) domain that matches your From: header domain to ensure SPF alignment.
Monitor DMARC reports diligently: Regularly analyze your aggregate reports to identify any unexpected SPF or DKIM misalignment issues and address them promptly. This helps to boost deliverability rates.
Views from the trenches
Best practices
Always aim for both SPF and DKIM alignment to ensure maximum email deliverability and resilience against forwarding issues.
Regularly review your DMARC aggregate reports to detect SPF misalignment issues and understand their impact.
Work with your Email Service Provider (ESP) to configure custom Return-Path domains for better SPF alignment.
Implement a DMARC policy gradually, starting with `p=none` to monitor results before moving to `quarantine` or `reject`.
Common pitfalls
Confusing SPF pass with SPF alignment, assuming a passing SPF record means DMARC compliance.
Ignoring SPF misalignment in DMARC reports, thinking DKIM alignment is always sufficient.
Not understanding how email forwarding can break SPF alignment and lead to DMARC failures.
Failing to set up DMARC monitoring, missing critical insights into email authentication issues.
Expert tips
Focus on domain-level alignment for DMARC, ensuring your From: domain aligns with either the SPF or DKIM authenticated domain.
Leverage DMARC reports not just for failure analysis, but to identify all legitimate sending sources and bring them into compliance.
Prioritize email authentication as a foundational element of your sender reputation, not just a technical checklist item.
Remember that user engagement is the ultimate deliverability factor, but authentication builds the trust needed for that engagement.
Expert view
Expert from Email Geeks says that SPF failing is not the main issue, rather it is that SPF is not aligned. The user may be misunderstanding the DMARC report itself.
2020-02-13 - Email Geeks
Expert view
Expert from Email Geeks explains that if the SPF domain is different from the From address domain, the domains do not align, leading to a DMARC fail. However, if DKIM alignment passes, DMARC will still pass.
2020-02-13 - Email Geeks
Key takeaways
When your DMARC report indicates that SPF is not aligned, it's a signal to investigate, but not necessarily a cause for panic. The crucial distinction is between an SPF authentication failure and an SPF alignment failure. An SPF alignment failure means the domains didn't match according to DMARC's rules, even if SPF itself authorized the sender.
For your emails to achieve optimal deliverability and protect your brand from spoofing, both SPF and DKIM should be properly configured and, ideally, aligned. While DMARC allows for flexibility (passing if either SPF or DKIM align), having both aligned provides a more robust and resilient email authentication posture. Consistent monitoring of your DMARC reports will ensure you maintain strong authentication and achieve better inbox placement. If you are experiencing issues with emails going to spam, check out our guide on why your emails might be failing.
bounce.getresponse.com) for the Return-Path, while your visible From: header is your domain (e.g., yourdomain.com). SPF passes because the ESP's domain is correctly authorized by their SPF record, but it doesn't align with yourdomain.com.
