Boxer allows users to create custom boxes by taking two or more folders from any of your email accounts and merging them into a new custom view. Creating a custom box is simply creating a new view of your e-mails, not a new folder and it does not delete any of your original folders.
1. Open up the slide-out navigation pane by tapping on the button in the top left corner of the inbox.
2. Tap on the "Edit" button. NOTE: Make sure you are in the combined view in order to see this option.
3. Tap on "Add Custom Box" to create a new one.
4. Type in a name for the custom box, or begin to select the folders you would like to add to it and it will automatically determine a name for the custom box.
5. Mark the checkbox next to each folder you would like to have sync with the custom box. When you have selected all you wish to sync, tap on the "Done" button.
6. Your new custom box will show up in the list of folders at the top of the slide-out navigation pane.