As with the system security, the messaging software security also has layers of its own, which can be separated into the following components:
There are several aspects of securing the directory beyond securing the basic server and operating system. These aspects are:
ACI— limiting permissions as to what people can see and do
Search limits— how many responses and how much time can be spent searching
SSL— enabling SSL support
Non-standard ports— not using ports 389 or 636 for LDAP or LDAP over SSL
This is not an exhaustive list of directory security issues, but it covers most of the options to secure the Directory Server protocols and access using these protocols.