Where you saw it: A Yahoo rejection citing sender requirements, or delivery falling across yahoo.com, aol.com and att.net at the same time.
Why it happens
- Missing DMARC on the sending domain, which Yahoo now expects from bulk senders.
- No one-click unsubscribe headers.
- Complaint rate above 0.3%, which Yahoo's feedback loop is the only way to see.
- Authentication that passes for a platform domain rather than aligning with your From domain.
- Not being enrolled in Yahoo's Complaint Feedback Loop, which leaves you blind to the number that matters.
The fix, in order
Match the Gmail work
The requirements are deliberately aligned. SPF, DKIM, aligned DMARC and one-click unsubscribe satisfy both, so do the work once.
Enroll in Yahoo's Complaint Feedback Loop
It is free, and it is the only way to see who marked you as spam on Yahoo-operated domains. Without it you are guessing at the number they enforce against.
Remember which domains this covers
Yahoo operates AOL and the AT&T family including sbcglobal.net and bellsouth.net. That is a substantial share of a US consumer list and it all follows these rules.
Watch asynchronous bounces after each send
Yahoo accepts at SMTP time and bounces later, so the real delivery picture appears in your bounce log the following day rather than in the send report.
Segment Yahoo addresses by engagement
Because no verifier can confirm a Yahoo mailbox, engagement history is the only quality signal available for this part of your list.
How to know it worked
The short version
- A test message to a Yahoo address shows all three mechanisms passing in the headers.
- Feedback loop reports arrive and show a complaint rate below 0.3%.
- Asynchronous bounce volume from Yahoo domains falls over subsequent sends.
Questions people ask
Why can I not verify Yahoo addresses before sending?
Because Yahoo returns a positive response to every recipient probe by policy, to defeat address harvesting. No verifier gets a real answer, and any confident verdict on a Yahoo address is inference.
Do these rules cover AOL?
Yes. AOL runs on Yahoo infrastructure, as do att.net, sbcglobal.net and bellsouth.net. One set of requirements covers all of them.
How do I see my Yahoo complaint rate?
Through their Complaint Feedback Loop, which is free to join. There is no equivalent of Postmaster Tools, so the feedback loop is the whole picture.