Below is what contents of the file should contain: # Begining of file # # LDAP Schema for Intranet Mail Routing # Reference: draft-lachman-laser-ldap-mail-routing-02 # # This file has been tested using OpenLDAP (www.openldap.org). # Save this file as mail-routing.oc.conf and add a line to your slapd.conf: # include /usr/local/etc/openldap/mail-routing.oc.conf # # Add an additional inattribute mailLocalAddress cis attribute mailRoutingAddress cis attribute mailHost cis objectClass inetLocalMailRecipient requires objectClass allows mailLocalAddress, mailRoutingAddress, mailHost # End of File This would deliver mail for tom@example.com to thomas@mailhost.example.com. dn: uid=dick, o=example.com, c=US objectClass: inetLocalMailRecipient mailLocalAddress: dick@example.com mailHost: eng.example.com [admin@linux named]$ cat supan.com.hosts | grep MX uio.supan.com. IN MX 5 uio.supan.com. uio.supan.com. IN MX 10 supan.com. @ IN MX 5 supan.com.