From the Home screen, tap Apps (in the Quick Access Bar) > Gmail > Menu key .
Tap Settings.
Tap General settings to change the settings for all accounts, including Archive & delete actions, Swipe to archive, Sender image, Reply all, Auto-fit messages, Auto-advance, Confirm before deleting, Confirm before archiving, and Confirm before sending.

NOTE
Tap each individual account to change its settings, including Inbox type, Inbox categories, Notifications, Inbox sound & vibrate, Signature, Vacation responder, Sync Gmail, Days of mail to sync, Manage labels, Download attachments, and Images.

Google Account settings