If you deal with a lot of e-mail, you’ll probably appreciate the more advanced swipe gestures that iOS 8 adds to the Mail app. No longer limited to merely deleting or archiving messages, iOS 8 allows you to perform up to four different actions simply by swiping either left or right on an item in your inbox.
By default, swiping right-to-left now displays a “Flag” option in addition to the Trash/Archive and More options, and you can also now swipe left to right to get an option to mark a message as read or unread. A long swipe in either direction will also automatically execute the appropriate actions, while a short swipe simply presents buttons that you can tap on to complete the action.
While the default options are somewhat useful, they may not match your normal way of working through your inbox, so the good news is that you can customize these settings even further.
Simply take a trip into the iOS Settings app, and in the Mail, Contacts, Calendars section you’ll find a setting for “Swipe Options”; from here you can choose to have the swipe-left gesture show a Mark as Read/Unread or Flag button, and the swipe-right gesture can be customized to Mark Read/Unread, Flag, or Archive the message..