How Can I Get gMail to Handle eMail Links on Web Pages?

When you first use gMail in Chrome, a little <> icon shows at the right end of the omnibar (aka address bar). This is a notification that gMail wants to install a "service handler" for email links. Click on this icon and check "Use CESU mail" and your gMail will now pop open whenever you click on a link to someone's email. If you accidentally "ignore" this prompt, the setting is buried but available in Settings --> Advanced Settings --> Content Settings (Privacy) --> Scroll down to "Manage Handlers" and delete the "ignored" handler to reset the prompt.