With UCS 3.2, we´ve recently replaced our Microsoft Windows Small Business Server 2003,. Its MS Exchange is not longer supported by MS since this mounth. As Collaboration-Solution, we use the zarafa platform yet, which is easy installable with Univention App-Center. UCS already operating as AD Domain-Controller yet. For migration of AD-Data, we use the new graphical Migration-Tool "Active Directory Takeover". It' s already installable with Unitvention App-Center. ( https://www.univention.de/produkte/ucs/app-katalog/app/details/adtakeover ).