iBooks Author: Send your book via email
If you use the macOS Mail application, you can quickly email your book directly from iBooks Author in a variety of formats.
Email your book
With the book open, choose Share > Send via Mail, and choose an option from the submenu:
iBooks Author File: Creates an iBooks Author file (with the extension .iba). Your recipient needs to have iBooks Author installed to open the file.
iBooks File: Creates an iBooks file (with the extension .ibooks). Your recipient needs to have iBooks installed on iPad, iPhone, or Mac to open the file.
PDF: Creates a PDF file (with the extension .pdf). Links work in the resulting PDF, but other interactive media, such as movies and 3D objects, might not work as expected.
A new mail message opens with the version of your book attached.
Edit the email message and click Send.