In the Gmail, “Reply” is the default button to reply single recipient. If user wants to send reply to the multiple recipients for that no direct “Reply to All” button is available. There is an option given in Setting > Lab, from where the user can enable “Reply to All” button. After enabling, it becomes default button. To get “Reply to All” button as default one follow the steps:
Step By Step:
1. Go to Setting (to the right top corner)
2. Click on Lab
3. In the list Enable “Default Reply to All”
4. Save it.
