In iOS 7, Apple introduced the option to add an "Unread" mailbox to the iOS Mail app, giving users a place to aggregate all incoming email for quick access. The feature was never widely publicized, and as a result, many iOS users today are unaware that it exists.
Adding an "Unread" mailbox takes just a few taps, but it's highly useful, especially when you've got a lot of incoming emails. We've created a video that shows how to enable the Unread mailbox on your iPhone or iPad, and below that, you'll find step-by-step instructions on the process.
Scroll down beyond the currently enabled mailboxes, and check the "Unread" box.
Use the hamburger button to move the Unread box to a spot that's most convenient for your usage habits.
Each incoming email will be filtered into the "Unread" mailbox as its received, and when read, the email will be removed from the box so you can always keep tabs on what hasn't been read. You can also filter emails by other parameters using specialized boxes found in the Mail app, including total emails received in a day, emails with attachments, flagged emails, and more.