Which operating system and browser >???
There have been some changes to Yahoo Mail
There is now BASIC where you can still set the number per page or the FULL
It is not available in the Full Featured version.
You could try the Basic option so that you can choose the number of email
displayed in your inbox pages.
You may lose other features you like in the Full
Featured version, it will be your choice what is most important to you.
If you decide to use Basic, here is how to set the number of messages per page:
Click on the little wheel to the right of the "hi .. your name"
On the next page, over on the right, under Mail Options, click on
You can then customize the number of messages under "behavior"
It might be a browser issue. Try using something
like Chrome or Firefox. They work well with yahoo mail.