If you are installing SIMS 3.5 for the first time, you need to populate the LDAP directory that SIMS uses to resolve incoming e-mail addresses and logins to mailboxes stored in SIMS.
Note - Messages sent to the SIMS system will not be routed until you populate the directory.
Populating the directory is a multi-phase operation which may require significant manipulation of data from NIS/NIS+/files for successful population.You need to populate the directory with entries for mail users, calendar users, user aliases, and distribution lists. The entries are created either from the /etc/passwd file and the mail /etc/mail/aliases file, or from the NIS/NIS+ equivalents.
See Chapter "Sun Directory Services Administration," in the Sun Internet Mail Server 3.5 Administrator's Guide for information about populating the directory.