Congratulations on the release of Carbonio CE! Great to see things come to life. Very happy to see some diversity.
It appears that the majority of the code is a direct fork of Zimbra (with renamed repositories). While this is a great base to build from, I am concerned about on-going fixes.
Given you have applied AGPL to the Zimbra code base, any fixes, changes, etc. would not be available upstream (given Zimbra GPL license). How does this affect on-going fixes? As Carbonio evolves, upstream (Zimbra) bug fixes, security fixes, etc. will become less compatible and potentially not work. Are you effectively taking on all support of the Zimbra code?
Great work! And Thanks!