Send List Email Your Way (Pilot)
Where: This update is available in Lightning Experience in Essentials, Professional, Enterprise, Performance, and Unlimited editions.
Why: Sending list emails through Outlook or Gmail ensures that the email looks like it's been sent directly from a user instead of by email automation. Recipients are more likely to open an email that looks like it’s been sent directly. Also, list emails are in the user’s sent folder, so the send history is intact.
How: From Setup, in the Quick Find box, enter Send through External Email Services, and then select Send through External Email Services.
When your users log in, they’re prompted to choose their preferred setting for list emails.