• Open Office files in Docs, Sheets, or Slides with one click: When you send or receive email with an Office file attached, you’ll see an edit icon that will open the file directly in Docs, Sheets, or Slides while preserving the original file format. 
• Easily reply to the email from within the file: Once the file is opened, you’ll have new options to respond to the email thread from the File menu in Docs, Sheets, or Slides. 

See images below. 

End users 

This provides a fast and convenient way to view, edit, and collaborate on emailed Office files directly in Docs, Sheets, and Slides. Previously, users would have to save a file to Drive before being able to use G Suite’s Office editing features. With this launch, they can open files more quickly and reply to email threads featuring Office files more easily. 

• Admins: There is no admin control for this feature. 
• End users: This feature will be ON by default. Use our Help Center to learn more about how to open an Office file in Docs, Sheets, or Slides from Gmail. 

• Rapid and Scheduled Release domains: Gradual rollout (up to 15 days for feature visibility) starting on December 10, 2020 

• Available to Google Workspace Business Starter, Business Standard, Business Plus, Enterprise Standard, and Enterprise Plus, as well as G Suite Basic, Business, Education, Enterprise for Education, and Nonprofits customers 
• Not available to Google Workspace Essentials and Enterprise Essentials customers 

• Cloud Blog: New ways Google Workspace works with tools you already use
• Google Help: Work with Office files using Office editing
• Google Help: Open & download attachments in Gmail