Regarding the checkbox to select multiple emails at once:
The checkbox at the top left corner, above the emails - which you can click on the select multiple emails in whatever folder you have open - selects 40 emails at-a-time AS LONG AS YOU DO NOT SCROLL DOWN THROUGH THOSE CHECKED EMAILS. If you do scroll down, once you reach the bottom of those first 40 emails, Yahoo Mail automatically checks every single other saved email in the folder, whether you want to delete them or not! We want to be able to scroll down through those first 40 emails to see if there are any among them that we do not want to delete. Having Yahoo Mail automatically check every email in the folder means we have to, instead, check emails one at-a-time so as not to end up having to uncheck purposely-saved emails all the way through the folder. Update Yahoo Mail so that it does not automatically add checks to every emails in the folder below the first 40 whenever scrolling down.
