1. We'll install all the necessary packages in one fell swoop: apt-get install krb5-clients sasl-bin libsasl-gssapi-mit libsasl-modules-plain libsasl-digestmd5-plain ldap-utils libnss-ldap libpam-ldap slapd
  2. If this is your primary server, you will also need to apt-get install krb5-kdc krb5-adminserver
  3. If this is not the primary server, I assume that you will be setting up to be a slave to the primary server, so you will need to seed your LDAP database with the contents of the primary. On the primary: sudo slapcat > tmp.ldif. Securely copy the file to the secondary, or replica: scp tmp.ldif replica:
  4. Copy this file to /etc/ldap/slapd.conf.
  5. Each of laser-mail.schema, inetDomain.schema, webmail.schema, and qmail.schema goes in /etc/ldap/schemas.
  6. Copy host.conf to /etc/ldap and edit the sasl-host line to replace the --FQDN-- to the hostname.