Step 1:  Click on the given link to add Mailcastr extension to your system from Microsoft Edge.

             Microsoft Edge Add-ons - mailcastr 


Step 2:  Click on "Get" then  "Add extension"




Step 3: Sign in to Gmail with your desired account



Step 4:  For activating Mailcastr, click on "Login now"



Step 5:  Sign in again with the same email id and you will be redirected to your Gmail home page.