Directly from a notification, you can see who sent an email and the context of it. You can either tap to get into the app, or take actions directly from the notification: Mark as read, or Reply (as defaults). By Pinching-out the notification in the “Notifications Center” you will be prompted with the following options: Reply, Mark as Done and Delete.
Please note that some devices do not support actions from the Notification Center.
Note: You can customize the notification actions using More (o o o) | Global Settings | Customize Menus | Configure Action Buttons | Configure Notification Actions.