I am working on a partial migration to zimbra. What I would like to do is move a couple of users to the zimbra server, and keep the rest on our current mail server.

Our current mail server is postfix+courier+ldap. I use transport_maps on our current postfix to forward mail to zimbra by smtp (user@domain.com smtp:[ip of zimbra server]. This works fine.

I am trying to attempt the same thing on the zimbra side for all the users that I have not migrated, so that zimbra will forward to our current mail server. Reading the Admin Manual, transport_maps looks for the zimbraMailTransport attribute. I have been so far unsuccessful in editing this attribute.

Am I going about this all the wrong way? Has anyone done this type of "partial migration", if so, what did you do?