With UCS 3.2, i´ve recently successful replaced our Microsoft Windows Small Business Server 2003, which MS Exchange is not longer supported by MS since this mounth. As Collaboration-Solution, i´ used the zarafa platform yet, which was easy to install with univention app-center. UCS already works as AD Domain-Controller yet. For migration of AD-Data, i´ ve used the new graphical Migration-Tool "Active Directory Takeover", with is already easy installabler about Unitvention App-Center. ( https://www.univention.de/produkte/ucs/app-katalog/app/details/adtakeover ).