Summary
Major mailbox providers such as Gmail, Yahoo, AOL, and Microsoft (Hotmail/Outlook.com) offer Feedback Loops (FBLs) that report spam complaints back to email senders. These FBLs are essential for maintaining a good sender reputation and improving email deliverability. Apple and most business mail systems typically do not report spam complaints. While some providers offer FBLs, they might not report 100% of complaints. Setting up these FBLs requires authentication and adherence to specific guidelines. Complaint rates are a critical factor influencing email deliverability; high complaint rates can lead to emails being junked or blocked.
Key findings
- Major FBL Providers: Gmail, Yahoo, AOL, and Microsoft (Hotmail/Outlook.com) are the key providers offering feedback loops.
- Non-Reporting Providers: Apple and most business mail systems generally do not report spam complaints.
- Partial Reporting: Many providers with FBLs may not report 100% of spam complaints.
- Importance of FBLs: Feedback Loops are crucial for monitoring complaint rates and maintaining a positive sender reputation.
- Complaint Rate Impact: High complaint rates, especially from major providers, negatively impact email deliverability.
Key considerations
- FBL Setup Requirements: Setting up FBLs requires authentication, adherence to guidelines, and specific header configurations.
- Comprehensive Monitoring: Utilizing multiple FBLs is necessary for comprehensive coverage across different providers.
- Proactive Complaint Management: Actively monitoring and addressing complaint rates is vital for preventing emails from being marked as spam or blocked.
- Reputation Impact: Consistent monitoring and management of spam complaints are crucial for maintaining a good sender reputation and deliverability.
What email marketers say
10 marketer opinions
Various mailbox providers offer feedback loops (FBLs) to report spam complaints back to email senders, enabling them to maintain good sender reputation and improve email deliverability. Major providers offering FBLs include Gmail, Yahoo, AOL, and Microsoft (Hotmail/Outlook.com). Apple and most business mail systems typically do not report spam complaints. Some systems don't report 100% of complaints. Setting up FBLs with major providers is crucial for tracking and addressing spam complaints.
Key opinions
- Major FBL Providers: Gmail, Yahoo, AOL, and Microsoft (Hotmail/Outlook.com) are key providers offering feedback loops to report spam complaints.
- Non-Reporting Providers: Apple and most business mail systems generally do not report spam complaints.
- Incomplete Reporting: Many providers do not report 100% of spam complaints.
- Feedback Loop Importance: Feedback Loops are critical for senders to monitor complaint rates and maintain a good sender reputation.
Key considerations
- FBL Setup: Setting up feedback loops with major providers requires authentication and adherence to specific guidelines.
- Complaint Rate Monitoring: Monitoring complaint rates, typically available through FBLs, is essential for maintaining good email deliverability.
- Reporting Accuracy: Be aware that not all spam complaints are reported, even by providers that offer FBLs.
- Sender Reputation: High spam complaint rates negatively impact sender reputation and email deliverability.
Marketer view
Email marketer from Mailjet shares that FBLs are offered by major mailbox providers, including Gmail, Yahoo, and Microsoft. They require senders to authenticate their email and adhere to specific guidelines to participate.
18 Jun 2024 - Mailjet
Marketer view
Email marketer from Litmus explains that monitoring complaint rates, typically available through FBLs, is essential for maintaining good email deliverability. High complaint rates negatively impact sender reputation.
22 Sep 2023 - Litmus
What the experts say
2 expert opinions
Feedback Loops (FBLs) are mechanisms that allow email senders to receive spam complaints from Internet Service Providers (ISPs). Complaint rates are a critical factor that mailbox providers use to filter mail, with high complaint rates from providers like Gmail and Microsoft leading to emails being junked or blocked.
Key opinions
- Feedback Loops (FBLs): FBLs allow senders to receive spam complaints from ISPs, helping maintain deliverability.
- Complaint Rate Impact: High complaint rates, especially from major providers like Gmail and Microsoft, negatively affect email deliverability.
Key considerations
- FBL Participation: Understanding which ISPs participate in FBLs is crucial for managing sender reputation.
- Complaint Rate Management: Actively monitoring and addressing complaint rates is vital to prevent emails from being marked as spam or blocked.
Expert view
Expert from Word to the Wise describes complaint rates from users as a critical factor mailbox providers use to filter mail. High complaint rates from providers such as Gmail and Microsoft result in emails being sent to junk or blocked.
18 Mar 2025 - Word to the Wise
Expert view
Expert from Spamresource.com explains that Feedback Loops (FBLs) are a method for email senders to receive spam complaints from ISPs. The major participants are detailed in the linked article.
10 Jun 2023 - Spamresource.com
What the documentation says
3 technical articles
Gmail, Microsoft (Hotmail/Outlook.com), and Yahoo offer Feedback Loop (FBL) programs that allow email senders to receive reports of user complaints marked as spam. Google's Gmail FBL helps identify problematic campaigns. Microsoft's SNDS provides data on IP addresses, including complaint rates. Yahoo allows senders to use their Complaint Feedback Loop to receive spam complaint reports. These programs require specific setups and headers to access the data.
Key findings
- Gmail FBL: Google provides the Gmail Feedback Loop for identifying campaigns causing spam complaints.
- Microsoft SNDS: Microsoft's Smart Network Data Services (SNDS) offers complaint rate data for Hotmail and Outlook.com.
- Yahoo Complaint Feedback Loop: Yahoo offers a Complaint Feedback Loop program to receive reports of user complaints.
Key considerations
- Setup Requirements: Setting up these FBLs requires specific headers and configurations in your emails.
- Data Usage: The data from these programs can be used to improve email deliverability and sender reputation.
- Provider Coverage: Each program covers a specific mailbox provider (Gmail, Microsoft, Yahoo), so you need to use multiple to get comprehensive coverage.
Technical article
Documentation from Yahoo explains that senders can use their Complaint Feedback Loop program to receive reports of user complaints marked as spam in Yahoo Mail.
19 Oct 2023 - Yahoo
Technical article
Documentation from Google Postmaster Tools details the Gmail Feedback Loop (FBL), which allows senders to identify campaigns causing spam complaints. It requires setting up specific headers in your emails.
15 Jul 2024 - Google Postmaster Tools
Are abuse reports and feedback loops (FBLs) still useful in email marketing, and how do they work with different email clients?
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How did Yahoo update their FBL ARF format and how did it impact ESPs?
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How should I format Feedback-ID for Gmail?
