You must enter the Javascript console on Chrome and input this command:
navigator.registerProtocolHandler('mailto', 'https://yourdomain.zmailcloud.com/?view=compose&to=%s','Cloudiance E-Mail');Note that "yourdomain" should be replaced by your custom domain name, without its suffix. So for instance if your domain name is domain.com, then the server name you'd use would be domain.zmailcloud.com.
Looking for the Javascript console on a Mac? Try Cmd+Opt+C.
