Source : Free On-Line Dictionary of Computing

Secure Multipurpose Internet Mail Extensions
     
         (S-MIME) A specification for secure
        {electronic mail}.  S-MIME was designed to add security to
        e-mail messages in {MIME} format.  The security services
        offered are {authentication} (using {digital signatures}) and
        {privacy} (using {encryption}).
     
        {(http://www.rsa.com/rsa/S-MIME/)}.
     
        (1997-05-10)