To properly administer S/MIME, you need to be familiar with the following concepts:
Basic administrative procedures for your platform
Structure and use of a lightweight directory access protocol (LDAP) directory
Addition or modification of entries in an LDAP directory
Configuration process for the Sun Java System Directory Server
Concepts and purpose of the following:
Secure Socket Layer (SSL) for a secured communications line
Digitally signed email messages
Encrypted email messages
Local key store of a browser
Smart cards and the software and hardware to use them
Private-public key pairs and their certificates
Certificate authorities (CA)
Verifying keys and their certificates
Certificate revocation list (CRL). (See When is a Certificate Checked Against a CRL?)