ROSA (RELS) experience?
 

Howdy,
Do any of you have experience with the above mentioned server for a small network with 6-8 clients?
Main focus on filesharing, email-server (like MS Exchange) for multiple domains, external fixed IP and ISP hosted DNS records which I can edit via browser..
Also I need similar to Active sync for mobile phones.

Looking at their site, it was only built and released late last year (RC = October, November release), so I think you'll be hard put to find anyone who has got it; and certainly no-one has much experience since then (except possibly the creators).

Personally, I'd go with something more established and give it a year to settle down, but that's just me.. :)

It appears to be based on RHEL, so you could go Centos (free rebuild of RHEL), if you like that distro.