The preview menu enables you to quickly open the current newsletter in your default web browser, in your default e-mail client or in SmartPreview, a tool that simulates viewing the newsletter on a smartphone device.
Use this feature to see what your newsletter will actually look like once it gets rendered by different types of target devices.

The first two menu items will differ according to whatever you have defined in your system as default browser and default e-mail client.

Preview menu
Preview menu
Click to enlarge

Note that the file shown by the preview feature is not fit to be used as the actual file for the final export, as images here are processed as temporary files or embedded into the body.
Use the Export feature to generate a proper file.

See also