Reading Your Messages
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 in the message to access the following options:
Gmail Inbox header icons
The Gmail Inbox
header icons include the Gmail Inbox icon 
, the Archive icon 
, the Delete icon 
, the Mark unread icon 
, and the Options icon 
.
Gmail message icons
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 Options icon
to reply to all, forward the
message, star (or remove star from) the message, print the message,
or block the sender.
Message action icons
Tap an action icon (at the bottom of the message) to reply, reply to all, or forward the message.