Kerio is announcing Kerio Connect 7 at this week’s Macworld Conference & Expo. Previously known as Kerio MailServer, marks the messaging server’s entry into the market of midsize, multi-office deployments, giving customers an option to link standalone servers into a single distributed domain system.

The advantages of a distributed domain become apparent for organizations with branch offices in different physical locations, according to Kerio. While companies often install separate messaging servers in offices located in other cities or countries for performance, security or compliance reasons, they often lose the benefits of a single collaboration server — most notably the ability to see the availability of coworkers in other offices.

Kerio Connect 7 allows companies to join their Kerio Connect servers into a single geographically dispersed cluster with servers aware of each other’s user groups, individual user’s availability, shared contacts in Global Address Lists, or shared resources such conference rooms. The management of distributed domains is a part of a newly introduced web-based Administration Console, providing remote management of Kerio Connect 7 from any modern browser.

Also, Kerio Connect 7 implements a new open source protocol CardDAV for address book synchronization. Apple Address Book, a CardDAV-compliant client in Mac OS X 10.6 (“Snow Leopard”), now syncs contacts directly with Kerio Connect 7. A configuration utility available through Kerio WebMail helps users setup their Address Book in a few clicks.

Kerio Connect 7 is available now from Kerio partners worldwide. It starts at US$450 for five users; additional user starts at $24. Kerio Connect 7 runs on Mac OS X, Windows, Linux and is also available as a VMware Virtual Appliance and Parallels Virtual Appliance. For more info, go to http://www.kerio.com/connect/whats-new .