Need to first define this objectclass??

[Kristina <kristina@fsas.fujitsu.co.jp>]

I would like to know how objectclasses work!  Can
I just go ahead and use the following objectclasses in
directory entries or do I have to first define the objectclass
somewhere in LDAP.

I want to use the "rfc822Routing" object class and its attributes
as in the example below taken from:
http://www.stanford.edu/~hodges/doc/draft-ietf-asid-email-routing-su-00.txt
Thanks
Kristina
(More details are here:)

****Example:*********
      objectClass: top
      objectClass: person
      objectClass: SUrfc822Routing
           .
           .
      cn: Im A. User
      cn: I. A. User
      cn: Im.A.User
           .
           .
      mail: Im.A.User@isp-r-us.com
           .
           .
      SUmailDrop: imasacnt@ImasMachine.isp-r-us.com
           
*************