Summary
When SPF is not aligned in a DMARC report, it means the domain used for SPF authentication (5321.MailFrom) does not match the domain in the 'From' header seen by recipients. This mismatch can lead to deliverability issues, as receiving servers may view the email with suspicion and flag it as spam or reject it entirely, especially if the DMARC policy is strict. DMARC falls back to DKIM if SPF fails alignment, but if neither aligns, the DMARC policy determines the email's fate. While DMARC only requires either SPF or DKIM to pass, failing SPF alignment weakens your email authentication posture. SPF is also susceptible to breaking during email forwarding, which can further complicate alignment. Ultimately, ensuring users want the mail remains a key factor in deliverability.
Key findings
- Domain Mismatch: SPF alignment failure signifies a mismatch between the 5321.MailFrom and the 'From' header domain.
- DMARC Fallback: DMARC falls back to DKIM if SPF alignment fails; DMARC policy dictates handling if both fail.
- Deliverability Impact: Non-aligned SPF can trigger spam filters, lower deliverability, and harm sender reputation.
- Legitimacy Concerns: It raises concerns about email authenticity and potential spoofing.
- Forwarding Issues: SPF can break with email forwarding, leading to alignment failures.
- Content Relevance: User engagement and the desire for the mail is critical for deliverability.
Key considerations
- DKIM Alignment: Ensure DKIM is properly configured and aligned to provide an alternative authentication method.
- DMARC Policy: Understand your DMARC policy (none, quarantine, reject) and its impact on emails with alignment issues.
- Domain Alignment: Investigate and correct any misconfigurations causing SPF alignment failures.
- Sender Reputation: Monitor your sender reputation and address any negative impacts from deliverability issues.
- Content Strategy: Focus on sending relevant and valuable content to ensure recipients want to receive your emails.
- 5321 vs 5322: In cases where they are different ensuring that your 5321.MailFrom domain uses an include for your sending domain.
What email marketers say
10 marketer opinions
When SPF fails to align in a DMARC report, it signifies that the domain authenticating the email via SPF (the 5321.MailFrom domain) doesn't match the domain displayed in the 'From' header that recipients see. This mismatch can lead to deliverability issues. While DMARC only requires either SPF or DKIM to pass, a failure in SPF alignment can trigger spam filters, potentially causing emails to land in spam folders or be rejected outright, especially when DMARC policies are set to quarantine or reject. Moreover, it raises concerns about potential phishing or spoofing, impacting sender reputation and weakening DMARC compliance. It's also important to note that SPF is vulnerable to breaking during email forwarding, which can cause alignment to fail. However, if DKIM is aligned and passing, the negative impact of SPF alignment failure can be mitigated.
Key opinions
- Domain Mismatch: SPF alignment failure indicates a mismatch between the authenticating domain and the displayed 'From' domain.
- Deliverability Impact: Non-aligned SPF can trigger spam filters, leading to lower deliverability rates.
- Spoofing Concerns: It can be perceived as a sign of potential phishing or spoofing, damaging sender reputation.
- DMARC Requirement: DMARC only requires SPF or DKIM to pass, but SPF alignment issues weaken DMARC compliance.
- Forwarding Issues: SPF is prone to breaking with email forwarding, causing alignment to fail.
Key considerations
- DKIM Alignment: Ensure DKIM is properly aligned as a backup authentication method when SPF alignment fails.
- DMARC Policy: Understand your DMARC policy (none, quarantine, reject) and its implications for handling emails with SPF alignment failures.
- Sender Reputation: Monitor your sender reputation and address any deliverability issues promptly.
- Domain Alignment: Investigate and correct any misconfigurations causing SPF alignment to fail regularly.
- Email Forwarding: Consider the impact of email forwarding on SPF alignment and implement solutions to mitigate issues.
Marketer view
Email marketer from Mailhardener explains that when SPF fails alignment, it means the domain that passed SPF authentication (the 5321.MailFrom, also known as the envelope sender or Return-Path) is different from the domain displayed in the 'From' header that recipients see. If SPF fails and alignment fails, deliverability will be affected negatively, especially if you don't have DKIM working.
9 Feb 2022 - Mailhardener
Marketer view
Email marketer from EasyDMARC shares that if SPF alignment fails, emails are more likely to be flagged as spam, especially if DMARC policy is set to quarantine or reject. This directly impacts deliverability and inbox placement.
10 Jun 2022 - EasyDMARC
What the experts say
5 expert opinions
When SPF fails to align in a DMARC report, it indicates a mismatch between the domain authenticating the email via SPF (specifically the 5321.MailFrom) and the domain displayed in the 'From' header. While SPF passing and DKIM alignment can mitigate this, SPF alignment failure raises questions about the legitimacy of the 'From' address, potentially leading to deliverability issues and increased spam filtering. DMARC will fall back to DKIM if SPF alignment fails, but if both fail, the DMARC policy dictates how the email is handled, often resulting in it being marked as spam or rejected. Ultimately, ensuring users want the mail being sent remains paramount for deliverability and inbox placement.
Key opinions
- Domain Mismatch: SPF alignment failure means the 5321.MailFrom domain doesn't match the domain in the 'From' header.
- DKIM Fallback: DMARC falls back to DKIM if SPF alignment fails.
- Legitimacy Concerns: It raises questions about the legitimacy of the email's 'From' address.
- Deliverability Impact: It can lead to deliverability issues and increased spam filtering.
- Content Relevance: Ensuring users want the mail is the biggest factor for deliverability.
Key considerations
- DKIM Alignment: Prioritize DKIM alignment as a crucial backup authentication method.
- SPF Record Updates: Including sending IPs in the primary domain's SPF record won't fix SPF alignment issues.
- DMARC Policy: Understand how your DMARC policy handles emails with failed SPF and DKIM alignment.
- Legitimate 'From' Address: Ensure the 'From' address accurately reflects the sending domain and is not misleading.
- Content Relevance: Focus on sending relevant and engaging content to ensure users want the mail and improve deliverability.
Expert view
Expert from Word to the Wise explains that the major problem is when SPF fails to align, it raises questions about whether the displayed 'From' address is legitimate. This is important as the receiving server can't use the valid SPF record to verify the email's authenticity, leading to potential deliverability issues and increased spam filtering.
10 Oct 2023 - Word to the Wise
Expert view
Expert from Email Geeks explains that the issue isn’t that SPF is failing, but rather that SPF is not aligned, meaning the domain in your 5321.from address is different from the domain in your 5322.from address. She indicates that if the SPF domain is passing, and DKIM alignment is working, then no action is needed.
11 Feb 2024 - Email Geeks
What the documentation says
6 technical articles
SPF alignment in DMARC reports refers to the matching of the domain used to authenticate the email via SPF (5321.MailFrom or Return-Path) with the domain displayed in the 'From' header. If these domains don't match, SPF alignment fails. DMARC.org specifies strict and relaxed alignment modes, with strict requiring an exact match and relaxed allowing subdomain matches. This lack of alignment can lead to DMARC failure, impacting deliverability and potentially causing emails to be rejected, quarantined, or handled according to the sender's DMARC policy. RFC 7489 emphasizes that this failure reduces the effectiveness of DMARC's protections.
Key findings
- Domain Mismatch: SPF alignment failure occurs when the 5321.MailFrom domain doesn't match the 'From' header domain.
- Alignment Modes: SPF alignment has strict (exact match) and relaxed (subdomain match) modes.
- DMARC Failure: Lack of SPF alignment can lead to DMARC failure.
- Deliverability Impact: DMARC failure impacts deliverability, potentially causing emails to be rejected or sent to spam.
- Reduced Protection: Failure to align reduces the effectiveness of DMARC's protections.
Key considerations
- Domain Verification: Ensure the 5321.MailFrom and 'From' header domains are properly aligned.
- Alignment Mode: Choose the appropriate SPF alignment mode (strict or relaxed) based on your domain structure.
- DMARC Policy: Understand your DMARC policy and how it handles emails with SPF alignment failures.
- SMTP Configuration: Ensure proper configuration of 'HELO' or 'MAIL FROM' SMTP commands to align with the 'From' header.
- DMARC Effectiveness: Strive for SPF and DKIM alignment to maximize the effectiveness of DMARC in protecting your domain.
Technical article
Documentation from Mimecast explains that when DMARC fails due to SPF misalignment or DKIM failure, the receiving email server will handle the message according to the sender's DMARC policy, which could be to reject the message outright, quarantine it (send to spam), or take no action. A DMARC failure can significantly impact email deliverability, especially for senders with a strict DMARC policy.
15 Sep 2022 - Mimecast
Technical article
Documentation from DMARC.org describes that SPF alignment has two modes: strict (s) and relaxed (r). Strict alignment requires an exact match of the domains. Relaxed alignment allows a subdomain match. If neither matches, alignment fails.
2 Nov 2021 - DMARC.org
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