How to Find Unread Emails in Gmail
Do you want to have a quick look at all your unread emails? If so, Gmail offers a couple of ways to do just that. You can perform a quick search that retrieves unread emails or make Gmail show all your unread emails first.
Search Gmail All Unread Emails Send Automatic Reply Emails Customize Gmail All Your Unread Emails First All Settings
Source: howtogeek.com