Email folders frozen

[gschill]

Wanted to delete all emails in Trash folder at once. Was not sure how to so I held down Trash folder with intention to swipe. Trash folder is now highlighted in red, but all folders are frozen (including Trash ). How can I unlock?

 

[gschill]

Folders seem to have unfrozen on their own. I would still like to know how to delete the entire contents of the Trash folder at once, however. Would appreciate help from those who are more knowledgeable. Thanks.