Did you know that Yahoo hosts email for over 127,179 domains? And the list of 127,179 domains comprises just the ones I know about. Those aren't all consumer domains. Yahoo has Yahoo.com, Rocketmail.com, Ymail.com, and all the various Yahoo domains for different countries, but they make up less than 600 of those domains. What else do they host? Sure, there are a lot of vanity (personal) domains. But, you'll also find that they host email for graphic arts companies, realty agents, investment bankers, sports teams, insurance agencies, online electronics retailers, medical clinics, and for many other companies big and small.
What does it all mean? It means that if you're a B2B sender, Yahoo is going to be significantly represented in your list.
This is yet another example of how B2C permission and sending requirements still apply to you if you're a B2B sender.
