When I looked at bringing e-mail in-house, I decided on OSX server over Microsoft Exchange. One of the great challenges was getting cardav/caldav support for my Windows users. Since everyone has been using Outlook for years, it’s very important to get contacts, calendars and e-mail all in one application. After struggling with different solutions (open source and commercial) for a week, I found eM Client. I can’t even begin to describe how pleased I was when I connected to our caldav server and voila! Not only did it connect, but it recognized ALL of the calendars I had created. This did NOT work on ANY other solution I tried. Within a matter of 30 minutes, I have replicated full Outlook/exchange capability in eM Client including stationary and signatures using caldav/carddav/imap. So far, feedback has been excellent. Users prefer the program performance and intuitive interface over Outlook 2007/2010. The extra features (weather, recent file attachments, etc) over Outlook demonstrate the maturity of your software. Well done!