I was thinking about SSL connections for the Due because there is more space and speed for that
I have searched fot it but I found nothing only some parts about the CyaSSL and integration in LwIP for RTOS, and
I have no idea how to integrate it, but this feature would be nice. Think the Due has the power for that.
And all the possibiltys, HTTPS, SSL/TLS for eMail connections and lots more...
Or PolarSSL looks comfortable for it https://github.com/polarssl/polarssl/blob/master/programs/ssl/ssl_mail_client.c
And I see Atmel puts allready some examples from it in the ASF but for the same uC that are worked in the Wifi-Shield.
Depends on this https://polarssl.org/discussions/platform-specific/atmel-microcontroller-wiznet-and-polarssl
and this https://www.brainspark.nl/kb/how-to/polarssl-tutorial
it should be possible to do this.