I use Yahoo Mail amongst other email providers and find that I am subjected to adverts to the right of my inbox and now even WITHIN my inbox. I have had enough and have installed the Firefox add-on below. It works and I am now advert free!
Here it is if you are similarly fed up…
https://addons.mozilla.org/en-US/firefox/addon/yahoomailhideadpanel/ – for Firefox
Thanks to the designers.