Fix your Spam Filters to actually remove the Spam that I mark
The very reason I almost NEVER use Yahoo Mail is because you can't take care of Spam. When I use my phone and mark something as Spam, it removes the email from my PHONE app listing with a stupid error saying my Spam filter is over its limit, but then when I come to the Browser application to check on my email, ALL of the emails that no longer show on my phone are STILL THERE on the Browser.
This is the reason you can't compete with the newer email providers. When something is Spam, and it NEVER actually gets filtered out of my feed, I am disincentivized to continue using your service for anything beyond what I have already signed up to see with it. And there is very little remaining.
Your goal might be get more people to use your service, and perhaps get them to pay more for it, but there are some very basic things that an email service should provide, and a Spam Filter that actually works, is one of them. If you're looking for some ideas to improve, please begin with existing services.
