Where is the Select ALL feature for email on the Galaxy S6? I am using the stock email (pop3) and have thousands of emails to delete - I find the "select all" in the "Trash Box" but not in the "In Box". Please help.

[Littleolady]

I am using the stock email (pop3) and have many email accounts.  With previous versions I have been able to "select all" emails and delete - now they have to be manually deleted individually - there has to be a way to get rid of old emails all at once.  There is that option in the "Trash" but not the "In Box".  Can someone please help with this situation?