It really depends... firstly, if other encryption standards are supported and secondly on the level of security that is required. For example, Cisco E-Mail Manager is a Web-based, thin client solution, written in Java. Clients log in to CeM, and perform all functions, through their Web browsers. CeM doesn't handle encryption internally. Instead, it uses Secure Socket Layer (SSL) encryption support to all inbound and outbound communication. So, i guess, SSL is the only option if you are working with CeM. Of late though, progress has been made on access security using a number of different encryption-based technologies such as S-HTTP and X.509 Certificate Authorities.
