In a recent update to Chrome, Google enabled a new website handler feature. You might have noticed the permissions button that now appears whenever you log in to Gmail using Chrome. If enabled, Gmail will automatically open and compose a new email message addressed to the email you click on while browsing the web. If you’ve enabled it and want to undo that, follow the instructions below.
Enable Gmail as Chrome’s Email Link Handler
Log in to Gmail using Chrome version 18.0.1025.45 or later. At the top of the page you should see a permissions bar asking for permission to “Allow Gmail (mail.google.com) to open all email links?” click Use Gmail.
Remove Gmail as your email link handler in Chrome
Open Google Chrome and click the Options (wrench) button at the top-right of the browser. From the drop-down list select Settings.
Navigate to the Under the Hood tab and click the Content settings… button.
Scroll down to the Content Settings list and click the Manage handlers… button.
All of your active (installed) protocol handlers will be listed on this page. Click the “remove this site” on the mailto handler to remove Gmail as your email link handler. Once removed, your system will revert back to opening email links in whatever default program you have assigned it.