Why don't I see a Preview button on a Soapbox Mailer Campaign?

If you're in a Soapbox Mailer Campaign, but are unable to see the Preview button, you might simply not have added the Preview button to the Soapbox Mailer Campaign Layout from the Getting Started With Soapbox Mailer guide.  To do this, just follow this step from the Getting Started with Soapbox Mailer guide.

Happy emailing!