It's $199 to $399 for a plastic case literally just containing a Raspberry Pi 3 Model B, running an outdated Raspian, and the software stack is extremely poorly developed. eg: their "secure handshake between devices" is basically two devices serving SMTP on port 26 instead of port 25.
It provides encryption, but no authentication nor authorisation. In short an ever so slight improvement over normal SMTP.
> The device uses self-signed certs throughout and they aren't even device specific. It's using the default ssl-cert-snakeoil.pem and ssl-cert-snakeoil.key in the Postfix config.