Summary
SPF failures in SFMC, even when seemingly passing, are multifaceted. Root causes include unaligned SPF passes (passing for SFMC but not the client domain), discrepancies due to different MIDs/IPs, incorrect SPF record syntax, not including Salesforce's IPs or the necessary `include` statement for SFMC, SPF alignment issues, misconfigured bounce domains, SenderID interference, exceeding DNS lookup limits, and the fundamental limitation of SPF in fully protecting the 'From' address. The fix involves verifying SPF syntax and domain alignment, correctly configuring bounce domains, including necessary senders (especially Salesforce), flattening SPF records, deprecating SenderID, thoroughly testing configurations, and understanding the need for DMARC in conjunction with SPF.
Key findings
- Unaligned SPF Passes: SPF passes for SFMC but not the aligned client domain.
- MID/IP Discrepancies: Configuration discrepancies arise from different Marketing Cloud IDs (MIDs) and IPs.
- Incorrect Syntax: Improper SPF record syntax leads to authentication issues.
- Missing Salesforce IPs/Include: SPF record lacks Salesforce's sending IPs or `include:mc.spf.salesforce.com`.
- Domain Alignment Issues: 'Mail From' domain doesn't match the 'From' domain, failing DMARC checks.
- Misconfigured Bounce Domain: Bounce (Return-Path) domain isn't properly configured or aligned.
- SenderID Interference: Failure of SenderID might incorrectly indicate SPF failure.
- Exceeding DNS Lookups: SPF record exceeds the limit of 10 DNS lookups.
- SPF Limitations: SPF alone doesn't fully protect the 'From' address.
- Multiple SPF Records: Multiple SPF records exist for the domain.
Key considerations
- Verify SPF Syntax: Ensure the SPF record is correctly formatted and error-free.
- Align Domains: Guarantee that the 'Mail From' and 'From' domains are aligned.
- Configure Bounce Domain: Correctly set up and align the bounce (Return-Path) domain.
- Include Salesforce: Add `include:mc.spf.salesforce.com` to the SPF record.
- Reduce DNS Lookups: Flatten SPF records to stay within the 10 DNS lookup limit.
- Deprecate SenderID: Consider deprecating SenderID in favor of SPF.
- Comprehensive Testing: Simulate real-world delivery scenarios to find hidden issues.
- Use Testing Tools: Test your SPF record by using tools such as `mail-tester.com` to identify configuration issues.
- Implement DMARC: Set up DMARC with SPF and DKIM for stronger authentication.
- Consolidate SPF Records: Ensure there is only one SPF record for the domain and combine directives into a single record.
- SFMC SAP Configuration: Correctly set up the SFMC Sender Authentication Package.
What email marketers say
9 marketer opinions
SPF failures in SFMC, despite appearing to pass, are often due to issues like incorrect SPF record syntax, alignment problems between the 'Mail From' and 'From' domains, misconfigured bounce domains, missing include statements for SFMC in the SPF record, or exceeding the DNS lookup limit. Ensuring proper SPF record formatting, aligning domains, correctly configuring bounce domains, including necessary third-party senders, testing configurations, and staying within the DNS lookup limit are crucial for resolving these issues.
Key opinions
- Syntax Errors: Incorrect SPF record syntax can lead to failures. Ensure the SPF record is properly formatted.
- Domain Alignment: SPF alignment issues, where the 'Mail From' (Return-Path) domain doesn't match the 'From' domain, can cause failures even if SPF appears to pass initially.
- Bounce Domain: A misconfigured or unaligned bounce domain (Return-Path) can lead to SPF failures.
- Missing Includes: Not including the necessary include statements, particularly for third-party senders like SFMC (`include:mc.spf.salesforce.com`), can cause SPF to fail.
- DNS Lookup Limit: Exceeding the SPF record's limit of 10 DNS lookups can cause it to fail.
- SPF Alone is not enough: SPF alone is not enough, but DMARC builds upon SPF and DKIM to provide stronger authentication
Key considerations
- Record Formatting: Double-check and correct any syntax errors in the SPF record.
- Domain Alignment: Ensure that the 'Mail From' (Return-Path) domain aligns with the 'From' domain.
- Bounce Domain Setup: Properly configure and align the bounce domain (Return-Path) with the sending domain.
- Include Statements: Include all necessary third-party senders, such as SFMC, in the SPF record.
- DNS Lookups: Flatten the SPF record to reduce DNS lookups, ensuring it stays within the limit.
- SPF Testing: Test your SPF record setup by using tools such as `mail-tester.com` to identify issues with your SPF configuration.
- SPF + DMARC: Implement DMARC in combination with SPF.
Marketer view
Email marketer from Stackoverflow explains that a common reason for SPF failing is not including the proper include statement, especially for third-party senders like SFMC. They said to make sure `include:mc.spf.salesforce.com` is added to your SPF record.
29 Jun 2022 - Stackoverflow
Marketer view
Email marketer from Mailjet shares that SPF alignment issues can cause SPF to appear to pass while failing DMARC checks. This occurs when the 'Mail From' domain (Return-Path) doesn't match the 'From' domain. They suggest ensuring both domains are aligned for proper authentication.
31 May 2022 - Mailjet
What the experts say
4 expert opinions
SPF failing in SFMC despite appearing to pass can stem from several issues including unaligned SPF passes (passing for SFMC but not the client domain), different MIDs/IPs causing configuration discrepancies, having multiple SPF records, or a disconnect between subdomain and top-level domain SPF records. Resolving this requires verifying subdomain SPF alignment, consolidating to a single SPF record, and comprehensive testing using real-world email delivery simulations to identify hidden problems.
Key opinions
- Unaligned SPF Pass: SPF might pass for the SFMC email sender but not the client's domain.
- MID/IP Discrepancies: Different MIDs (Marketing Cloud IDs) and IPs can lead to SPF configuration discrepancies.
- Multiple SPF Records: Having multiple SPF records is a common mistake leading to SPF failure.
- Subdomain Disconnect: A disconnect between subdomain and top-level domain SPF records can cause issues.
Key considerations
- Verify Subdomain Alignment: Check and verify subdomain SPF alignment due to SFMC's custom domain setup.
- Single SPF Record: Consolidate to a single SPF record by combining multiple directives.
- Comprehensive Testing: Test setup using tools simulating real-world delivery scenarios to identify hidden issues.
- Check for MID/IP Configuration: Verify consistent SPF configurations across all MIDs and IPs
Expert view
Expert from Email Geeks suggests it could be an unaligned pass, where SPF passes on the SFMC email sender but not the aligned client domain.
10 Oct 2021 - Email Geeks
Expert view
Expert from Spam Resource, John Levine, explains that one common mistake that leads to SPF failing even when it appears correct is having multiple SPF records. He said to ensure there is only one SPF record for the domain, and to combine multiple directives into a single record.
7 Jan 2023 - Spam Resource
What the documentation says
4 technical articles
SPF failures in SFMC, despite appearing to pass, can be attributed to several factors. These include missing Salesforce sending IPs in the SPF record, multiple SPF records existing for the sending domain, the inherent limitation of SPF in protecting the 'From' address visible to recipients, and improper configuration of the SFMC Sender Authentication Package (SAP). Addressing these issues requires properly configuring SPF records to include Salesforce IPs, ensuring only one SPF record exists, understanding the limitations of SPF, implementing DMARC for stronger authentication, and correctly setting up the SFMC SAP, including private and bounce domains.
Key findings
- Missing Salesforce IPs: SPF records lacking Salesforce's sending IPs can lead to failures.
- Multiple SPF Records: The existence of multiple SPF records for a domain is a common cause of SPF failure.
- Limited 'From' Protection: SPF alone doesn't fully protect the 'From' address seen by email recipients.
- SAP Configuration: Incorrect setup of the SFMC Sender Authentication Package (SAP) can result in authentication issues.
Key considerations
- Include Salesforce IPs: Ensure the SPF record includes Salesforce's authorized sending IPs.
- Single SPF Record: Verify that only one SPF record exists for the sending domain.
- Implement DMARC: Implement DMARC alongside SPF and DKIM for robust email authentication.
- Configure SAP: Properly configure the SFMC Sender Authentication Package (SAP), including private and bounce domains.
Technical article
Documentation from SFMC explains the Sender Authentication Package (SAP) and how it brands your emails. It outlines the different components, including setting up a private domain for branding and a separate domain for bounces. This source provides the steps to properly authenticate your sending domain.
12 Mar 2022 - SFMC
Technical article
Documentation from RFC explains that SPF relies on the 'MAIL FROM' address, also known as the envelope sender or Return-Path. It says that this address is often different from the 'From:' header address, which users see.
21 Jun 2023 - RFC
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