You can not get rid of the box but you could install an ad blocker such as AdBlock Plus which will at least leave you with an empty ad box which doesn't appear as intrusive.
Eureka! Very many thanks.
I'd never in a hundred years have worked that out. How very counter intuitive, though. You'd think if there is a box marked Email in heavy type that is where you should enter the email address.
Another convoluted "improvement" like having to hover over three different lists in order to move an email into a folder.
You can just drag and drop an email that is in your email inbox list into a folder.
Yes, I did use that method but, as I explained to another contributor who offered help, I have very arthritic hands and found it difficult to be precise and sometimes had to have two or three tries before hitting the right folder. How can this be an "improvement" on the old one click "move to" but thank you, once again.
And if anyone with any influence is watching, please make the square boxes next to new messages much larger. Plenty of room for that - (b..... the aesthetics). My fingers are arthritic too - and so yours may be when you get old.