We're looking around for a new mail server solution, since our mercur (www.atrium.de) server is just too unstable.
Preferably it should run on windows (we're just not at home on the *nix platforms), have all it's config options in a sql database, provide anti-spam and anti-virus out of the box, have a feature-rich webmail client and be tailored for a small ISP.
Our specs: ~700 Domains, ~4000 Users
Thanks in advance for all your tips!
Cheers,
Mike