Why can’t I send a test email to outside email addresses?

Test emails can only be sent to team members of your newsletter. This means that if they’re not listed as one of the team members of your Publication (not to be confused with one of your subscribers), you won’t be able to send them a test email of your newsletter. 

To remedy this, add the person as a team member in your account here. An email will be sent to the person and after they accept the invite, you will be able to send them test emails of your newsletters.