Mailto: calls not blocked by phonegap whitelist on iOS

I am trying to restrict mailto: on iOS Phonegap so that I can create an app where the user cannot be redirected to the mail client. I made the necessary changes in the /config.xml but still all the mailto: calls open the default mail client. Is there any way to restrict it in config.xml? I could not find sufficient documents for this on phonegap website.

Yup, you can add this to your config.xml to prevent any external apps from launching.

access origin="tel:*" launch-external="yes" 
//allow using external phone app

access origin="mailto:*" launch-external="no"
// prevent mail app from taking over

Cordova 3.6.0 introduces a second whitelist, for restricting which URLs are allowed to launch external applications. In previous versions of Cordova, all non-http URLs, such as mailto:, geo:, sms: and intent, were implicitly allowed to be the target of an tag. Because of the potential for an application to leak information, if an XSS vulnerability allows an attacker to construct arbitrary links, these URLs must be whitelisted as well, starting in Cordova 3.6.0