HOW TO MAKE EMAIL LINKS OPEN IN GMAIL INSTEAD OF YOUR MAIL APPLICATION
If you use Gmail instead of Outlook or Mail, you probably find it quite annoying whenever you click a link like this one. If you use Google Chrome as your browser, do the following.
If that icon doesn't appear, then follow these steps
Click this icon in the top right of your window
For other browsers, follow this link for steps to follow, including Firefox, Safari and Internet Explorer