Best Practices What is an Email Feedback Loop? By MailChannels | 2 minute read Email feedback loops (FBLs) allow email receivers to tell a sending network about the complaints their users are generating about email originating from the sending network. By tuning in to FBL data, sending networks can identify problematic email traffic originating from their IP address space, such as spam messages. This information can help to pinpoint and then shut down spammers. How do FBL providers know where to send feedback? FBL providers use two main methods to determine the destination to which feedback messages will be sent: By IP – AOL, Comcast, Cox, and most other FBLs require you to register your IP address space with them in order to receive abuse feedback messages. On their registration forms, you will need to provide your abuse contact email address. You must re-visit their registration form each time you add an IP address to your network. By Domain using DKIM – Yahoo! and some newer FBLs allow you or your users to register the domains from which they send with the Yahoo! FBL. DKIM is used to verify domain ownership before sending abuse information in relation to a particular message. Should I sign up? If you send email from a dedicated IP address which is under your control, then you should register with all major feedback loops in order to make sure you are staying on top of any spam originating from your IP address. If you do not control the IP address from which you send email, then your service provider should be registered. How can I sign up? Many large email receivers provide FBLs, which you can freely register for by clicking on the links below: AOL Bluetie Comcast Cox Earthlink FastMail Hosted Email Mailtrust MSN/Hot NetZero/Juno Rackspace RoadRunner Synacor Terra (Brazil) United Online USA.net Verizon Yahoo Zoho Google’s Gmail service also offers a feedback loop, which is currently in beta. To indicate your interest in the Gmail FBL, visit this signup form. Not all senders will be accepted into their FBL program.