Make 'Reply all' your default setting

1. On your computer, go to Gmail.
2. In the top right, click Settings See all settings.
3. In the 'Default reply behaviour' section, select Reply all.

You can still choose to reply to just one person, but 'Reply to all' will be the first option.

Reverting To ’Reply’ as your default setting

1. On your computer, go to Gmail.
2. In the top right, click Settings See all settings.
3. In the 'Default reply behaviour' section, select Reply.

You can still choose to reply to all, but 'Reply' will be the first option.