You can send a sample of each email to a defined list of recipients. First open the "Preview" pane.
From there, choose Send Sample.
You'll be invited to select the email(s) to send and add recipients by either selecting users, groups or directly typing any email address.
The sample email(s) will go out within seconds after you hit Send. (Please verify your spam folder if you don't get it within 2-3 minutes. The email will come from email@example.com)
Email samples are a simulation of the final email and may not be an exact match of the final email sent by Marketo.