Zimbra open source hybrid with Zimbra NE

Hi Guys,

Wondering if OS edition can be made hybrid or domain sharing with Zimbra NE? Lets say I have example.com and zimos.example.com installed for OS edition while I need certain people to move off to zimbra NE which is assume zimne.example.com. Is it possible?

Also, how can we make zimbra hybrid with pure postfix server?

Can someone shed light on these scenarios?