Ask Al: Help, no Yahoo CFL volume!

Hey, Al! My company has sent approximately 200,000 email messages in the past month to Yahoo! Mail recipients, but we haven’t received even a single complaint back via our ISP Feedback Loop. Is that normal?

No, that is not normal! If you’re sending mail en masse, you’re going to get some non-zero number of complaints back. Even if it’s all fantastically opt-in and there’s no chance of somebody getting an unwanted email message, Yahoo's ISP Feedback Loop, which they call the Complaint Feedback Loop, is always going to faithfully report along any complaints it is given, and that always will include a low number of complaints from people who truly did sign up for the email message. (Keeping in mind that a complaint isn't what kills your deliverability dead; it's a high number or high percentage of complaints that does it.)

Thus, I suspect something is broken. Probably something on this checklist:

  1. You're not signing with DKIM or if you are, not with the correct domain. Keep in mind that Yahoo’s Complaint Feedback Loop (CFL) - aka the Yahoo FBL, is only going to send spam complaints back for mail authenticated with DKIM. Are all your messages being signed with DKIM authentication? Does the d= domain in that DKIM signature match the domain name registered with Yahoo?
  2. That DKIM signing domain is not registered with Yahoo correctly. To get complaints back via the Yahoo FBL/CFL feed, you need to register that domain with Yahoo specifically, and complete the registration process – you must be able to receive a registration email that Yahoo will send, and you'll need to copy the code from that email and back into the signup form. And note that even after all of that, it could take 24-48 hours before complaints begin to flow. (And note that you’re only going to get “new” complaints fed to you – any prior complaints about your mail will not be forwarded.)
  3. What about the selector? I always register with the Yahoo CFL with an asterisk (*) as the selector, indicator that I want to get reports about any complaints about mail from this domain, with any DKIM selector. If you're not sure what your DKIM selector is, or don't want to worry about re-registering for the FBL if/when you increment your DKIM key, stick with an asterisk.
  4. Your mail is going to the spam folder; people can't complain about mail in the spam folder. The ISP has already labeled it spam. Goes without saying.
  5. Your ESP or send platform is not properly handling the FBL requests. If your ESP is set up to process FBL complaints (hopefully they are), they have a special address that Yahoo is supposed to be forwarding those messages to, and then the ESP processes the complaint, logs it, and unsubscribes the complaining recipient. Time to talk to your ESP and ask them to help confirm that everything is working properly on their end.

When in doubt, re-submit the domain to the Yahoo CFL. I’ve seen that fix things many times. I’m not entirely sure why, but it does seem sometimes like a domain will just “drop off” or disappear from Yahoo’s feedback loop. To register a domain with the Yahoo CFL, go here, and click on "Complaint Feedback Loop: Set up and manage."

Keep in mind that sometimes ESP platforms sign up for these things for clients, so be sure to coordinate with your sending platform. I've had ESP customers accidentally misconfigure a once-working FBL to forward all complaints to ... some random guy, where it will totally fill up and overwhelm that guy's mailbox. You don't want that. That'll break a whole bunch of things and make multiple people unhappy -- most importantly, your subscribers, who will no longer stop getting mail when they complain.

Find Frequently Asked Questions (FAQs) about the Yahoo CFL (and answers) here.



  1. About p.2 - CFL sends a verification code that needs to be input on the same page, not a link as far as I've seen

    1. Good point, Dima! I will correct this. Thanks.


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