Someone is bound to have done this. However searching did not produce any results so I am posting a new topic. I would like to achieve some sort of synchronization between my address books, which are stored either in Gmail or in Exchange accounts which I have with a hosting provider, and the 3cx server. As this is not an in-house Exchange server I am not able to access it to set up impersonation accounts. What I do have is an in house Windows 2012 r2 Server on which I might be able to set up an LDAP server. Unfortunately I have been unable to figure out how to get my address book from Google or exchange into an LDAP server running on Active Directory. There seems to be no simple way to do this and even then it will be basic import av data, not synchronization.