You can delete all of your emails on Yahoo Mail using "Select All" repeatedly, or you can use the "Clean your Inbox" tool to ...

If your Gmail account has a big red number showing hundreds or even thousands of unread emails, it’s probably slowing you down and eating up your Google storage space.

You can mark any message as unread on Signal in the Android and iPhone versions of the secure-messaging app.

Do not instantly delete spam. Keep it briefly to rescue mistakes, report phishing, train filters, then purge everything on schedule. The post Why You Should Never Delete Your Spam Emails, According to ...