Where: This change applies to orgs with Salesforce Inbox and Enhanced Email enabled in Lightning Experience in Enterprise, Performance, and Unlimited editions.
Who: Users with the Use Inbox user permission, available with a High Velocity Sales, Sales Cloud Einstein, or Inbox license.
How: To schedule an email, sales reps select Send Later in the email composer.
The rep then selects the date and time and clicks Schedule.
To let your reps manage scheduled emails, use Edit Page to add the Send Email Later - Pending List component to any object’s home page, including the Salesforce homepage.
Using that component, reps can reschedule, edit, or delete an already-scheduled email.