Open the email with the ePub on your Apple device. Tap the link for ePub and select "open in Kindle" or "open in iBooks". (You may have to double-click to initiate the download)
NOOK, NOOK HD, or NOOK HD+ USERS:
Download the ePub to your computer.
Connect your device to the Computer with its USB cable. (Windows users will see MyNOOK or NOOK appear as a new drive in My Computer. Mac users will see a MyNOOK or NOOK drive on their desktop. You'll see an additional drive if you have a MicroSD card inserted in your device)
Copy the ePub file from it location on your computer to the My Files/Books folder in the MyNook or NOOK window.
Disconnect your device
On your Nook HD or HD+. from the Home Screen, tap LIBRARY and then tap the OPTIONS and then tap REFRESH to update your NOOK's Books folder. On your NOOK, tap from the QUIV NAV bar, tap LIBRARY and tap the SYNC button to refresh your NOOK's My Documents folder.
Connect your eReader to your computer using the USB cable. Your eReader will prompt you to either keep reading or manage your library. You can use your computer or the Desktop Application to add books and manage your eReader.
Using the Navigation Pad, select "Manage Library." Windows users, your computer should detect that you connected a new device.
Windows users, when prompted for an action, select "Open folder to view files." A window should open, showing the contents of your eReader. Mac users, on your computer, open your Finder application.
Windows users, in another Explorer window, navigate to where you stored the eBooks you want to move to your eReader. Mac users, select KOBO eReader from your list of devices. Finder should display the contents of your eReader.
Windows users, drag and drop your eBooks into the eReader window. You can now disconnect your eReader and read your new books. Mac users, users, in another Finder window, navigate to where you stored the eBooks you want to transfer to your eReader. Drag and drop your eBooks into the eReader window. You can now disconnect your eReader and read your new books. Turn on your eReader and find your new ebooks. They will be in the "ebooks" area if the file is ePubs, or in the "documents" area if they are PDFs.