This feature allows users to send one email from a deal to multiple people that can be: deal clients, other contacts in deal, deal team members (users) and referrers.
In order to send an email to multiple contacts, enter your deal, then in Deal View select “Send Email” button from top right corner.
That way you will be able to email all your deal clients, other contacts (from deal), referrers and team members (other users).
Select Sender
Choose Template
Choose Recipients
Click Send
Check this article on how to create email templates.
Once email is sent it will appear in deal notes.
Check this video to see this feature in action: