Please once you have confirmed it works, edit the very first post of this very long thread and modify subject, inserting [SOLVED] as explained [ur=http://forum.zentyal.org/index.php/topic,4139.0.htmll]here[/url].
I hope you learned, during this investigation, as much as I did
It's always amazing, at least from my side, to realize after lot of exchange, that technical problem was very simple but the two main issues are, as often, communication and alignment regarding basic concepts (here: how DNS works).
If you look carefully at what you have now in term of design, this is no more nor less than what standard documentation describes
Keep in mind limitation I raised about Samba and .local TLD