The process to insert your flipbook into an e-mail is very simple and does not take long at all. First of all, you have to open your publication and click on the one you wish to add to the email. Second of all, open the "Embed" submenu and right click on the cover of the publication to save the image (See more features of Embed).
After that, click on the "Info" submenu and copy the link. Open the email and paste the image you saved from "Embed", right click on it and choose the "Insert Hyperlink" option. Paste the link which you saved when you were at the "Info" submenu and save it. And now you have the flipbook inserted in your message (See what Info submenu contains).
Remember: If you want to update your brochure and keep the same link it's very important to use the "Overwrite" button