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
While viewing a message, you can tap the message action icons on the Gmail Inbox header or the message header to access the following options:
The Gmail Inbox header icons include the Gmail Inbox icon , the Archive icon , the Delete icon , the Read/Unread icon , and the Menu options icon .
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 Menu options icon to reply to all, forward the message, or print the message.