From your Gmail Inbox, tap a conversation that contains the message you want to read. The conversation opens to the first new (unread) message, or to the first starred message, if you’ve previously starred a message in the conversation.

Tap to set labels for the message to help organize your messages.
Tap the Contact's picture to open Quick Contact.
Gmail Message Header
Gmail Inbox Header
Tap the Gmail icon
to return to your Gmail Inbox.
Tap the Delete icon
to move the email to the trash
folder.
Tap the Mark as unread icon
to return the message to an unread
state.
Tap the Move to
to move the message to the inbox.
Tap the Menu options icon
to access more options.
Tap the Contact’s picture to open the Quick Contact options.
Tap the Favorite icon
to mark it as a favorite.
Tap the Reply icon
to reply to the sender.
Tap the Forward icon
to forward to other person.
Tap the Menu options icon
to reply to all, add star, or
print the message.