The original issue, which still stands, was that currently service lacks proper support of CalDAV, and CardDav, which every single half-decent email service in 2015 supports out of box.

You can as well move to completely different service - does not have to be Microsoft - such as gmail, google apps, fastmail, online exchange, etc. Help to resolve the issue with the current product. LocutusEstBorg's comment is a bit off topic - suggesting to use different product does not