Summary
Feedback Loops (FBLs) and the Abuse Reporting Format (ARF) remain valuable in email marketing for maintaining deliverability and sender reputation. FBLs, offered by mailbox providers, forward complaints to senders, enabling them to identify and remove complainers from their lists. While Microsoft's JMRP offers early warnings, FBLs don't cover all email addresses; coverage can vary. Spam reports in webmail clients trigger FBLs, unlike those in IMAP clients (e.g., Apple Mail), which train local spam filters. High spam rates, monitored by tools like Google Postmaster Tools, negatively impact deliverability; aim for below 0.1%. ARF standardizes abuse reporting, while tools like Microsoft SNDS help identify problematic IPs. Proactive management, list cleaning using FBL data, and understanding complaint thresholds relative to list size are essential for effective FBL use.
Key findings
- Deliverability and Reputation: FBLs directly improve email deliverability and protect/enhance sender reputation by facilitating the removal of complainers.
- Technical Functionality: FBLs are services from ISPs that forward complaints and ARF provides a standard reporting format.
- Webmail Focus: FBL reports are primarily triggered by spam complaints in webmail interfaces, not IMAP clients.
- Monitoring is key: Monitoring tools are important, Google provides overall data on spam rate, Microsoft helps find problematic IPs.
- Threshold variations: Acceptable complaint thresholds vary by list size to avoid triggering spam filters.
Key considerations
- Define Objectives: Establish clear objectives for using FBLs to guide strategy.
- Adjust strategy for different clients: Recognize the different reporting behavior of webmail versus IMAP clients and adjust strategies accordingly.
- Cleanup Lists: Prioritize swift removal of recipients who submit spam complaints through FBLs.
- Keep rates low: Monitor spam complaint rates relative to list size and strive to keep rates below 0.1%.
- Active FBL management: Actively manage and respond to FBL reports to demonstrate commitment to responsible sending practices.
What email marketers say
9 marketer opinions
Feedback Loops (FBLs) and Abuse Reporting Format (ARF) are vital tools in email marketing for maintaining a good sender reputation and ensuring deliverability. FBLs help identify and remove subscribers who mark emails as spam, which prevents future complaints. ARF provides a standardized format for ISPs to report email abuse, aiding senders in understanding and addressing issues like spam complaints and list bombing. Consistently monitoring and managing FBLs allows senders to avoid being blocklisted and improves inbox placement, even for transactional emails. Utilizing FBL data for list cleaning and proactively responding to feedback improves trust with mailbox providers.
Key opinions
- Deliverability Impact: FBLs directly improve email deliverability by enabling senders to identify and remove subscribers who mark emails as spam.
- Reputation Management: Actively managing FBLs enhances sender reputation, signaling to mailbox providers a commitment to responsible sending practices.
- Early Issue Detection: FBLs can identify issues such as content problems or authentication failures, particularly in transactional emails mistakenly marked as spam.
- ARF Standard: The Abuse Reporting Format (ARF) provides a standardized method for ISPs to report email abuse, helping senders understand the nature of complaints.
Key considerations
- Consistent Monitoring: Regularly monitor FBL reports to promptly address complaints and prevent further deliverability issues.
- List Hygiene: Use FBL data to maintain a clean email list by removing subscribers who consistently mark emails as spam.
- Proactive Response: Respond proactively to FBL reports to demonstrate a commitment to responsible sending and improve trust with mailbox providers.
- Transactional Emails: FBLs are valuable even for transactional emails, helping to identify and resolve issues that cause legitimate messages to be marked as spam.
Marketer view
Email marketer from Reddit user u/EmailNoob states that FBLs are essential. They provide direct feedback from recipients who mark your emails as spam, which helps you clean your list and improve your sending reputation.
26 Mar 2022 - Reddit
Marketer view
Email marketer from Mailjet Blog explains that FBLs help identify and remove subscribers who mark emails as spam, improving sender reputation and deliverability. They also help in understanding user behavior and refining email strategies.
24 Oct 2023 - Mailjet Blog
What the experts say
4 expert opinions
The usefulness of Feedback Loops (FBLs) depends on the specific goal. Microsoft's JMRP offers an early warning signal, though FBLs don't encompass 100% of email lists; one source's B2C data showed over 40% coverage. FBL reports typically originate from users clicking 'This is Spam' in webmail interfaces, not from marking as spam in IMAP clients like Apple Mail or Outlook (which instead train Bayesian filters). FBLs help identify and remove complainers, protecting sender reputation. While a complaint rate exceeding 0.1% is often cited, the appropriate threshold varies by list size to avoid triggering ESPs and blocklists.
Key opinions
- Variable FBL Coverage: FBLs don't cover all email addresses, so alternative monitoring methods may be needed for complete oversight.
- Webmail vs. IMAP: Spam reports in webmail clients trigger FBLs, but similar actions in IMAP clients do not, instead influencing local spam filters.
- Reputation Protection: Removing recipients who complain via FBLs directly helps maintain and improve sender reputation.
- Complaint Thresholds are Fluid: A complaint rate of 0.1% is a general guideline, but the acceptable level depends on list size to avoid triggering alarms.
Key considerations
- Define Goals for FBL Use: Determine specific objectives for using FBL data to guide monitoring and response strategies.
- Account for Client Differences: Recognize that spam reporting behavior varies between webmail and IMAP clients, affecting the data received via FBLs.
- Prioritize Complainter Removal: Act swiftly to remove recipients who submit spam complaints through FBLs.
- Adjust Complaint Thresholds: Tailor complaint rate thresholds based on list size to prevent unwarranted deliverability issues.
Expert view
Expert from Spamresource explains that feedback loops let you know which recipients complained about your mail. By removing those recipients from your list, you prevent more complaints, protecting your reputation.
12 Apr 2023 - Spamresource
Expert view
Expert from Email Geeks explains that the usefulness of FBLs depends on the desired outcome. Microsoft's JMRP can provide an early warning signal. FBLs don't cover 100% of a list and checking their B2C data, over 40% of email addresses are at domains with an FBL.
12 Dec 2021 - Email Geeks
What the documentation says
4 technical articles
Feedback Loops (FBLs) are offered by mailbox providers (ISPs) to forward complaints about email messages back to senders, allowing them to remove users flagging emails as spam. The Abuse Reporting Format (ARF) is a standardized format for reporting email abuse. Google Postmaster Tools highlights that high spam rates negatively impact deliverability to Gmail users, and FBLs can help monitor and reduce these rates by identifying problematic recipients; a spam rate below 0.10% is recommended. Microsoft SNDS provides feedback loop data, enabling senders to monitor complaint rates and identify problematic IPs, facilitating the removal of repeat offenders.
Key findings
- Complaint Forwarding: FBLs forward user complaints from mailbox providers back to senders.
- Standardized Reporting: ARF provides a standard format for reporting email abuse.
- Deliverability Impact: High spam rates, as monitored by Google Postmaster Tools, negatively impact deliverability.
- Microsoft SNDS: Microsoft SNDS helps identify problem IPs with high spam complaint rates.
Key considerations
- Remove Complainers: Remove users who flag emails as spam based on FBL data.
- Meet Spam Rate Goals: Aim for a spam rate below 0.10% to maintain good deliverability to Gmail users.
- Monitor Complaint Rates: Regularly monitor complaint rates using tools like Microsoft SNDS.
- Identify Problem IPs: Use Microsoft SNDS to identify IPs generating the most spam complaints.
Technical article
Documentation from Validity explains FBLs are a service offered by mailbox providers (ISPs) that forward complaints about email messages back to the sender. This allows senders to remove users who flag emails as spam from their lists.
31 Mar 2022 - Validity.com
Technical article
Documentation from Microsoft SNDS (Smart Network Data Services) provides feedback loop data to senders. It allows senders to monitor complaint rates and identify which IPs are generating the most spam complaints from Microsoft email users. Senders can use this to remove repeat offenders.
6 Aug 2023 - Microsoft
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How critical are Feedback Loops (FBLs) for sender reputation, and how often do they require re-enrollment?
How do email service providers process feedback loop (FBL) emails to identify users and manage suppressions?
How do ESPs collect Yahoo FBL data using double DKIM signing?
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