Gmail displays conversations and messages from one account at a time, or all of your inboxes together. If you set up more than one email account on your phone, you can display their inboxes individually and easily switch between them.
From your Gmail inbox, tap the Accounts and labels icon tap the current account, then tap the account that contains the email you want to read.
The number of unread messages is displayed to the right of each account and folder.
Accounts and Labels Icon
Tap here to open a list of account choices and account labels.