Are there specific requirements for sending to Yahoo/AOL?

If you're sending bulk email and Yahoo Mail or AOL Mail are in your audience, you can't treat their requirements as optional. Since early 2024, Yahoo and AOL have formalized what they were already quietly enforcing. Fall short, and your emails either get throttled or rejected outright.

Here's what they actually require.

Authentication has to pass. SPF and DKIM must both pass for every message you send. DMARC is required too, and at minimum you need a policy of p=none to start. Yahoo checks all three. If your SPF record is broken or your DKIM signature isn't validating, expect delivery problems fast.

One-Click Unsubscribe is now mandatory for bulk senders. This is the RFC 8058 standard, and it means your emails need a List-Unsubscribe header that lets recipients unsubscribe with a single click directly from their inbox, without being sent to a landing page that asks them to confirm again. Most modern ESPs handle this for you, but if you're sending through a custom setup, it's worth double-checking your headers. Yahoo takes this seriously.

Spam complaint rates matter more here than almost anywhere else. Yahoo and AOL draw the line at 0.3%, but the real target is below 0.1%. If your complaint rate climbs above that, you'll feel it in your delivery. Yahoo runs its own Feedback Loop (FBL) program, which sends you complaint data so you can act on it. Signing up for that isn't required, but it's one of the smartest things a bulk sender can do. (Without FBL data, you're flying blind on complaints from Yahoo inboxes.)

Volume spikes will get you throttled. Yahoo doesn't like sudden jumps in sending volume, especially from newer IPs. If you're building out a new sending infrastructure or warming up a new IP address, go gradually. Start small, build a track record, then scale up. Trying to send millions of emails from a cold IP on day one is a reliable way to get rate-limited.

List hygiene is non-negotiable. High bounce rates and spam trap hits damage your reputation with Yahoo quickly. If your list has addresses you haven't mailed in years, or data you're not confident about, cleaning it before a big send is worth the effort.

Yahoo publishes documentation and tools for senders at postmaster.yahooinc.com, including guidance on FBL enrollment and troubleshooting. It's a good bookmark if Yahoo is a significant part of your audience.

Not sure if your authentication is set up correctly before sending? Our free SPF checker and DKIM lookup can spot the obvious gaps in under a minute. And if something's already broken and emails aren't getting through, the SOS hotline is there for exactly that situation.