- DKIM: Sign your mail with DKIM (Domain Keys Identified Mail). It's an email authentication technology, and the original version of it was actually invented by Yahoo folks. You'll need this to be able to participate in the Yahoo ISP Feedback Loop (FBL), and it helps make it easier for Yahoo to identify your mail, giving you a subtle deliverability boost, if you're a good guy.
- FBL: Sign up for the Yahoo Complaint Feedback Loop. They call it a CFL, almost everybody else calls it an FBL (Feedback Loop). This allows you to receive complaints back from Yahoo when somebody complains about your mail by making it as spam in the Yahoo! Mail user interface. You'll unsubscribe those folks, preventing further complaints, but if you're smart, you'll also use this data to identify which list segments or signup sources are more problematic than others. The theory being that higher complaints leads to poorer inbox delivery. Use FBL/CFL data to figure out which segments to stop sending to, before they cause a deliverability problem. Yahoo no longer has a dashboard where you can check FBL participation -- now you just submit it to their system, wait a few days for approval, and then complaints should in theory start coming. If you think you submitted it a few years ago but can't remember, go ahead and submit it anew.
- Engagement: Focus on your most engaged subscribers. Yahoo is very much engagement driven (as is Gmail, as are other ISPs). Meaning that if you have a lower-than-average percentage of subscribers opening and clicking on your email messages, you're much more likely to find your mail relegated to the spam folder. If you're in the business of shoveling a ton of "barely wanted" mail, like endless attempts to convert free users to paid users, good luck. This type of mail almost always has a low engagement rate when measured by percentages of mail sent and it can be darn near impossible to get solid inbox delivery, unless you take some pretty dramatic strategic steps to modify what you do to convert those potential paying customers.
- DMARC: Implement DMARC, if you can. This can get a bit tricky, and I might be a little bit ahead of the curve on this one, but bear with me here. DMARC is "an email-validation system designed to detect and prevent email spoofing," wherein you publish a DNS record that helps instruct ISPs when they can discard mail that purports to be from you, but fails validation checks. My thought here is that the more you do to ensure that your mail is proven legitimate, the better off ISPs can get at blocking illegitimate (phishing, spoofing) mail. There's a potential for an indirect deliverability benefit to you. (And I don't know about Yahoo with certainty, but I've seen some data that suggests other ISPs provide a modest deliverability boost when a DMARC record is found.) DMARC takes some technical knowhow that not everybody possesses. My recommendation? Partner with somebody like Proofpoint or Agari and have them guide you through the process.
- Read and Register: Read Yahoo Mail's Deliverability FAQs page. Submit your sending IP addresses to Yahoo by way of this form. Be honest and clear when describing your list hygiene and mailing practices. You'll notice that I list this as number five, not number one. That is because I feel it's important to get your "sending ducks in a row" before reaching out to an ISP. Any ISP is going to want you to make sure you're already putting your best foot forward -- doing everything you can from a technical perspective and best practices perspective (opt-in only) to ensure that your mail is in compliance with the ISP's policies. Reaching out for help with deliverability issues-- when you are NOT in compliance with the ISP's policies-- is a lost cause. You'll either get through the door but then kicked right back out again, or they'll turn down your request, or they'll simply not reply. It'll be very frustrating. ISPs, even big ones run by big companies, don't care about "your big brand" and they already "do know who you are" -- so focus on making sure your marketing program is executing correctly before ever trying to play that relationship card.
What is the path to deliverability success at Yahoo! Mail? Here are five simple considerations that will help point you in the right direction.