Why does Google Postmaster Tools report SPF failures for ActiveCampaign sends even when SPF passes?

Key findings

• SPF alignment vs. raw SPF: Google Postmaster Tools reports SPF failures based on domain alignment, meaning the Mail-From domain (envelope sender) must match or align with the From address domain visible to recipients. Raw SPF passing, where the sending IP is authorized by the Mail-From domain, is a separate check.
• ESPs and Mail-From domains: Many Email Service Providers (ESPs) like ActiveCampaign use their own domains for the Mail-From address. This results in SPF passing for the ESP's domain, but failing alignment for your domain in Google Postmaster Tools.
• Fluctuating failure spikes: The periodic spikes in SPF failure in GPT, despite consistent non-alignment, can occur because GPT aggregates data over time. If a domain is also used to send emails via other services that do achieve SPF alignment (e.g., GSuite for transactional emails), GPT might report higher SPF success on those days. When the volume of non-aligned traffic (like ActiveCampaign campaigns) dominates, the failure rate spikes.
• Shared IP addresses: Different shared IP addresses used by an ESP may send varying volumes of aligned versus non-aligned traffic, which can influence the perceived SPF success rate in Google Postmaster Tools on specific days.
• DMARC's role: DMARC explicitly requires either SPF alignment or DKIM alignment to pass authentication. If SPF fails alignment, DMARC will only pass if DKIM is properly configured and aligned. This is why DMARC reports (e.g., from DMARCIAN) consistently show SPF failing when alignment is not met.

Key considerations

• Focus on DMARC compliance: While SPF non-alignment is reported, the primary goal for deliverability is to ensure your emails pass DMARC authentication. If SPF alignment is not feasible with your ESP, ensure your DKIM record is correctly configured and aligned.
• Consult your ESP's documentation: Review ActiveCampaign's (or your specific ESP's) guidance on email authentication. They often provide instructions for setting up custom DKIM or custom return-path domains to help with DMARC alignment. See ActiveCampaign's guide on SPF and deliverability.
• Monitor all authentication types: Pay close attention to your DKIM and DMARC success rates in Google Postmaster Tools, alongside SPF. A high DKIM success rate (especially with alignment) can compensate for SPF alignment failures under DMARC.
• Understand data aggregation: Recognize that Google Postmaster Tools aggregates data from all emails sent from your domain, which can lead to variations based on the mix of sending sources and their respective authentication setups.

Key opinions

• Confusion with GPT's SPF data: Marketers frequently find Google Postmaster Tools' SPF reporting to be counter-intuitive, showing failures despite individual email checks confirming SPF passes.
• Alignment as the culprit: A common observation is that DMARC-level SPF failures due to non-alignment are the primary reason for GPT's SPF failure reports.
• ESP Mail-From domains: Many marketers acknowledge that ESPs, including ActiveCampaign, use their own domains for the Mail-From address, which inherently prevents SPF alignment with their client's From domain.
• Inconsistent GPT reporting: Marketers are puzzled by the fluctuating nature of GPT's SPF failure reports, where some days show passes and others show failures, even with consistent sending practices.
• Seeking principle understanding: There's a clear desire to understand the underlying principles of how GPT processes and presents SPF authentication data, especially in scenarios involving multiple sending IPs or other sending services.

Key considerations

• Prioritize DMARC pass: Given that SPF alignment is often not possible with ESPs for the Mail-From domain, marketers should focus on ensuring DKIM is properly configured and aligned to achieve a DMARC pass.
• Engage ESP support: Directly contacting ESP support (like ActiveCampaign) can provide specific insights into their authentication setup and any known issues or recommendations for improving GPT reporting. See also, BlueLena's advice on GPT for newsletters.
• Holistic view of authentication: Instead of isolating SPF data, marketers should analyze the overall authentication dashboard in Google Postmaster Tools, including DKIM and DMARC, to get a complete picture of their email authentication health.
• Educate clients: It's important to explain to clients that SPF failures in GPT due to alignment issues are a common and expected behavior with many ESPs, as long as DMARC passes through DKIM.

Key opinions

• GPT's alignment focus: Experts clarify that Google Postmaster Tools' SPF success rate specifically measures SPF alignment with the From header domain, not just the raw SPF pass. This is a crucial distinction for understanding GPT reports.
• Shared IP influence: The use of shared IP addresses by ESPs and varying sending volumes from different sources (aligned vs. unaligned traffic) can lead to the observed spikes and inconsistencies in GPT's SPF reporting.
• Mail-From vs. Header From: Understanding that SPF checks the Mail-From (envelope sender) domain while DMARC requires alignment with the Header From domain is key to interpreting authentication failures.
• DMARC enforcement: DMARC's explicit requirement for alignment means that even if raw SPF passes, the lack of alignment with your From domain will result in a DMARC SPF failure.
• Expected ESP behavior: For many ESP configurations, SPF non-alignment in GPT is expected. Experts advise focusing on achieving DMARC compliance through DKIM alignment in such cases.

Key considerations

• DMARC as the deliverability gatekeeper: Emphasize that achieving a DMARC pass (via either SPF or DKIM alignment) is crucial for inbox placement and reputation.
• DKIM alignment for DMARC: If SPF alignment isn't an option with your ESP, ensure DKIM is fully configured and aligned with your From domain. This is often achieved through CNAME records provided by the ESP.
• Custom return-path configuration: Explore if your ESP allows for a custom return-path domain (bounce domain) using a CNAME record, as this can enable SPF alignment with your primary domain.
• Interpret GPT data in context: Remember that GPT provides an aggregated view of authentication results. Don't panic over SPF alignment failures if your DKIM is robust and DMARC is passing.Word to the Wise discusses this authentication context.

Key findings

• Google's SPF reporting metric: Google Postmaster Tools documentation indicates that its SPF success rate specifically assesses if the SPF-validated domain aligns with the From header domain, not just if the raw SPF check passes.
• DMARC alignment requirements: RFC 7489 (DMARC) mandates that for DMARC to pass via SPF, the Mail-From domain must align with the From header domain (organizational domain match). For a clear understanding, refer to DMARC tags and their meanings.
• ESPs' authentication setups: ESPs typically offer options like setting up DKIM CNAMEs for clients' domains to ensure DKIM alignment, which can then satisfy DMARC requirements even if SPF alignment is not present.
• Authentication dashboard purpose: Google Postmaster Tools' authentication dashboard helps senders assess their overall email authentication health and DMARC compliance, which is key for deliverability.

Key considerations

• Understand DMARC's core function: Familiarize yourself with how DMARC works to unify SPF and DKIM authentication with domain alignment. This is fundamental for modern email security and deliverability. For more, learn what SPF stands for.
• Consult Google's official documentation: Refer directly to the Google Postmaster Tools Help documentation to understand how they calculate authentication rates and what each metric signifies.
• Prioritize DMARC compliance: The ultimate goal should be a passing DMARC policy, which assures receiving mail servers of your email's legitimacy, irrespective of individual SPF alignment reports if DKIM is aligned.