In the recent times many are using Firefox browsers and also many are utilizing Google’s free email service – Gmail. In this stage, to open every Gmail to see for new mails received is difficult. When you have many Gmail accounts, every time there is no need to login.
To check multiple Gmail accounts this add-on is available for Firefox browser users named ‘Gmail Manager ‘. This multiple account Gmail checker addon even supports Gmail 2-step authentication. You can obtain this addon through the link: https://addons.mozilla.org/en-US/firefox/addon/gmail-manager/