Little tinkering around... I installed a Zarafa server with Z-push active sync. It works pretty well with Jolla's exchange sync. Just one question... has anyone been able to change the default calendar in Jolla? I can only create new meeting to default calendar which doesn't sync to my server. If I create an appointment in server, it will sync to my device but I just can't create new ones from the phone. Also, it would be nice to be able to sync all contacts to the server, but so far I haven't found out how to do it.