Encrypted Message eXchange (EMX) is designed for organizations that want to enable customers and partners to communicate securely using a private label secure web-based environment. EMX is a fully hosted solution, which does not require any investment in hardware or software. Members can easily and quickly create one or more member communities for ongoing confidential communications or on a transaction by transaction basis. Messages are encrypted using industry trusted standards public key infrastructure (PKI) and S/MIME for strong encryption and digital signature.”]
Source: https://www.darkreading.com/attacks-breaches/echoworx-debuts-emx