Currently, I am running ZCS 8 open source and would like to upgrade it to ZCS 8 network edition.

Is there a way to do this without losing the user email accounts that are currently being using with the open source edition?

That is, can someone here explain to me the steps to follow or direct me to a Zimbra expert.

I want to be able to backup all the user accounts on the open source edition and then restore all the user accounts to the network edition ?

thank you