Concept
Reuse email content with Lightning and Classic email templates in the Send Email action. If your email template has merge fields, you can use the recipient record or a related record to populate the merge fields. Or, you can use both. Previously, you couldn’t use email templates in the Send Email action.
Where: This change applies to Lightning Experience and Salesforce Classic in Essentials, Professional, Enterprise, Unlimited, and Developer editions.
How: For example, to send an email to a contact using an email template with Contact and Account object merge fields, set Email Template ID to the ID of the email template to use. Then, set Recipient ID to the contact record’s ID.
