Undeletable email in Yahoo Mail app

A

AC Question

I am receiving what looks like a spam email in my Yahoo mail inbox, however this email only appears in my Yahoo mail app on my phone (Samsung Galaxy S4 using Android version 4.2.2); it doesn't show up if I access my mail via my iPad or on my PC.

The subject line and sender name on the email keep changing each time I open the app. It has variously been listed as 'Gold Coast Hotel Deals' from trivago (I've never been a trivago member), 'Brain Training Games' from Lumosity (again, never signed up to such a company), and a couple of other things that I can't remember offhand. Where the checkbox usually appears to allow you to move/delete the email from the inbox list, there is a $ symbol surrounded by a circle of outward-facing lines (like rays of the sun). Some of the email subject lines also show the word 'sponsored' on the right hand side, and some of them have an 'Install Now' button.

I'd like to know how I can get rid of this without opening the email.