Use Journey Optimizer to send email messages to your customers. You can create, personalize, and preview messages in the Email Designer.
Email deliveries can be created:
In a Journey: once you added an Email activity to your journey, and defined basic settings, use the Actions: Email right pane to create the content for the message. Learn how to create a journey
In a Campaign: once you created a campaign, select Email as your action and define basic settings. Learn ow to create a campaign
If this is your first time creating an email, make sure the email channel has been configured. Learn more