How did Yahoo update their FBL ARF format and how did it impact ESPs?

Summary

Yahoo updated its FBL ARF format to provide more granular data and enhanced header information, but the changes caused initial parsing issues for ESPs. The updated format included enhanced header information, which allows ESPs to more accurately identify the source of spam complaints and improve their filtering mechanisms, and made some MTAs unable to process the reports. As ARF is a standard format, ESPs needed to adjust their systems to correctly interpret the new format to maintain accurate complaint tracking and avoid misinterpreting user feedback, but the updates would inherently affect the structure and fields within the ARF reports, leading to parsing errors for systems not updated. Smaller ESPs and independent senders struggled more than larger providers, and the situation led to confusion due to drops in reported complaints, so ESPs needed to prepare for potential rollbacks. The impact was mainly on the technical side, where parsing and interpretation of the reports needed updates, leading to short-term challenges in identifying and managing problem senders until they adapted. Eventually, Yahoo rolled back the changes, and things returned to normal.

Key findings

  • Parsing Issues: Yahoo's FBL ARF update caused initial parsing issues for many ESPs.
  • Adaptation Required: ESPs needed to update their systems to correctly interpret the new format.
  • Spam Filtering Impact: Difficulties in parsing led to a temporary reduction in spam filtering efficiency and deliverability.
  • Disproportionate Impact: Smaller ESPs struggled more than larger providers due to resource constraints.
  • Reporting Inaccuracies: Parsing errors resulted in a drop in reported complaints, causing confusion and concerns about feedback loop accuracy.
  • Enhanced Data: Yahoo provided more granular data and enhanced header information in FBL reports to improve spam identification.
  • Rollback Event: Yahoo eventually rolled back the changes, resolving the parsing issues.

Key considerations

  • System Updates: ESPs should ensure systems can quickly adapt to changes in FBL ARF formats.
  • Resource Allocation: Smaller ESPs should allocate sufficient resources for timely adaptation to format changes.
  • Accuracy Verification: ESPs should verify the accuracy of feedback loop reporting post-update to maintain reliable data.
  • Rollback Preparedness: ESPs should prepare for potential rollbacks and ensure systems can handle them smoothly.
  • Sender Management: ESPs should prioritize quick identification and management of problem senders, especially during FBL format changes.
  • Enhanced Data Utilization: Utilize the more granular data and enhanced header information to improve spam source identification.

What email marketers say
13Marketer opinions

Yahoo updated its FBL ARF format, causing initial parsing issues for ESPs due to changes in the Abuse Reporting Format. This required ESPs to update their processing algorithms to correctly interpret feedback loop data, impacting spam filtering and deliverability. Smaller ESPs and independent senders faced greater challenges adapting. The situation led to confusion due to drops in reported complaints, and ESPs needed to prepare for potential rollbacks.

Key opinions

  • Parsing Issues: The Yahoo FBL update initially caused parsing issues for many ESPs.
  • Required Adaptation: ESPs needed to update their systems to correctly interpret the new format.
  • Impact on Spam Filtering: Difficulties in parsing led to temporary reduction in spam filtering efficiency.
  • Disproportionate Impact: Smaller ESPs struggled more than larger providers due to resource constraints.
  • Reporting Inaccuracies: Parsing errors resulted in a drop in reported complaints, causing confusion.

Key considerations

  • System Updates: Ensure systems can quickly adapt to changes in FBL ARF formats.
  • Resource Allocation: Smaller ESPs need to allocate sufficient resources for timely adaptation.
  • Accuracy Verification: Verify the accuracy of feedback loop reporting post-update.
  • Rollback Preparedness: Prepare for potential rollbacks and ensure systems can handle them.
  • MTAs Processing: Not all MTAs were able to process the reports - so ensure yours can or be prepared to find alternative ways to handle the data.
Marketer view

Email marketer from Email Geeks shares that Yahoo updated their FBL ARF format, potentially impacting ESPs and those processing complaints themselves, noting that the change may be unintentional and that original headers are stripped.

November 2023 - Email Geeks
Marketer view

Email marketer from Reddit user u/EmailExpert mentions that some smaller ESPs and independent senders struggled more than larger providers because they lacked the resources to quickly adapt to the format changes. This created a temporary competitive disadvantage.

September 2021 - Reddit
Marketer view

Email marketer from Email Geeks believes some MTAs can parse the new format only if they are using VERP.

August 2024 - Email Geeks
Marketer view

Email marketer from Email Geeks confirms that things should be getting back to normal.

September 2021 - Email Geeks
Marketer view

Email marketer from Email Geeks mentions that some MTAs (PMTA, Halon) can still process the complaints, while others (GreenArrow) cannot.

December 2022 - Email Geeks
Marketer view

Email marketer from StackOverflow user ARF_Parser mentioned that there were increased discussions and questions among developers on Stack Overflow related to ARF parsing difficulties after Yahoo’s update, indicating a widespread challenge in adapting to the new format.

December 2024 - StackOverflow
Marketer view

Email marketer from Email on Acid explains that ESPs had to ensure their systems were updated not just for the new format but also for potential rollbacks if Yahoo encountered issues, making the adaptation process more complex.

August 2023 - Email on Acid
Marketer view

Email marketer from Email Geeks states they are aware of the differences in Yahoo's FBL ARF reports and are researching the issue.

February 2025 - Email Geeks
Marketer view

Email marketer from EmailGeekForum user FBL_Watcher discusses that many ESPs initially saw a drop in reported complaints due to the parsing errors, leading to confusion and concerns about the accuracy of their feedback loops.

February 2024 - EmailGeekForum
Marketer view

Email marketer from Mailjet Blog shares that Yahoo's changes required ESPs to update their processing algorithms to correctly interpret the feedback loop data. This adaptation ensures that ESPs can efficiently act on user complaints to maintain high deliverability rates.

September 2022 - Mailjet Blog
Marketer view

Email marketer from Email Geeks announces that Yahoo is rolling back the changes and reports should return to normal later that day, including duplicates from the past two days.

December 2023 - Email Geeks
Marketer view

Email marketer from EmailVendorSelection shares that the Yahoo FBL update initially caused parsing issues for some ESPs because of changes in the ARF (Abuse Reporting Format). ESPs needed to adjust their systems to correctly interpret the new format to maintain accurate complaint tracking and avoid misinterpreting user feedback.

December 2022 - EmailVendorSelection
Marketer view

Email marketer from SparkPost Blog explains that after the Yahoo FBL update, numerous ESPs reported increased difficulties parsing feedback loop data, leading to delays in processing user complaints. This resulted in a temporary reduction in the efficiency of spam filtering mechanisms, potentially affecting deliverability.

February 2022 - SparkPost Blog

What the experts say
2Expert opinions

Yahoo's FBL ARF updates necessitated that ESPs adjust their systems for processing feedback data, mainly affecting the technical aspects of parsing and interpreting reports. Some ESPs initially faced difficulties in handling complaint data, leading to short-term challenges in identifying and managing problem senders until they adapted.

Key opinions

  • ESPs Required to Adjust Systems: Yahoo's ARF changes required ESPs to adjust their systems.
  • Parsing/Interpretation Impact: The technical side of parsing and interpreting reports needed updates.
  • Complaint Data Issues: Some ESPs had trouble processing complaint data initially.
  • Sender Management: Identifying and managing problem senders was more challenging initially.

Key considerations

  • System Updates Needed: ESPs should regularly update systems for feedback data processing.
  • ARF Understanding: Need for clear understanding of ARF format changes.
  • Problem Sender Identification: Prioritize quick identification and management of problem senders.
Expert view

Expert from Spam Resource explains that Yahoo's FBL ARF changes required ESPs to make adjustments to their systems to correctly process the feedback data. The impact was mainly on the technical side, where parsing and interpretation of the reports needed updates.

October 2024 - Spam Resource
Expert view

Expert from Word to the Wise explains that due to changes that Yahoo made, some ESPs initially had trouble processing complaint data, which led to difficulties in identifying and managing problem senders. This was a short-term impact as ESPs adapted.

December 2022 - Word to the Wise

What the documentation says
3Technical articles

Yahoo Mail updated its FBL reports to include more granular data and enhanced header information to help ESPs identify spam sources and improve filtering. As ARF is a standard format, these changes affected the structure and fields of ARF reports, leading to parsing errors for systems not updated. FBL programs are critical for maintaining sender reputations, and Yahoo's ARF changes directly influenced how ESPs handle abuse reports and filter spam.

Key findings

  • Granular Data: Yahoo provided more granular data in its FBL reports.
  • Enhanced Headers: Yahoo's updated format included enhanced header information.
  • ARF Impact: Changes to ARF reports impacted systems relying on the older format.
  • Sender Reputation: FBL programs and ARF format directly affect sender reputations.
  • Spam Filtering: The changes influenced ESPs' ability to filter spam effectively.

Key considerations

  • Update Systems: ESPs need to update systems to handle new ARF formats.
  • Improve Identification: Use enhanced data for better spam source identification.
  • Maintain Reputation: Ensure FBL programs adapt to keep good sender reputations.
Technical article

Documentation from Yahoo Help explains Yahoo Mail has updated its Feedback Loop (FBL) reports to provide more granular data regarding user complaints. The updated format includes enhanced header information, which allows ESPs to more accurately identify the source of spam complaints and improve their filtering mechanisms.

June 2024 - Yahoo Help
Technical article

Documentation from Microsoft explains that Feedback Loop (FBL) programs are essential for ESPs to maintain good sender reputations. Yahoo's ARF format changes directly impacted how ESPs process and respond to abuse reports, influencing their ability to filter spam effectively.

November 2023 - Microsoft
Technical article

Documentation from RFC Editor explains that ARF is a standard format for reporting email abuse. Yahoo's updates would inherently affect the structure and fields within the ARF reports, meaning that systems relying on a rigid interpretation of the older format would experience parsing errors until updated to reflect Yahoo's changes.

November 2023 - RFC Editor