Hardware:
Intel Xeon E3110 Processor, 4GB RAM, 2 x 1 TB SATA Drive

Platform:
Ubuntu 8.04LTS 64 Bit

Software RAID1
(Thanks to Falko Timme for a howto (How To Set Up Software RAID1 On A Running System (Incl. GRUB Configuration) (Debian Etch) | HowtoForge - Linux Howtos and Tutorials) and continuous support during setup

Server is behind NAT Router, so I needed to setup SplitDNS. (guides: Zimbra::wiki)

Zimbra:
Version 6.0.8
Approx. 86 users (and increasing...)
At present serving 1 domain, may be 2 more in near future.
Running successfuly since November 11, 2010.

Backup:
Backing up to NAS.
Thanks to Heinzg for backup script ([SOLVED] Yet Another Backup Script for Community Version)

Special thanks to everybody who has helped (and have been helping) me through forums. Without your help, this setup could not be up and running. Thanks to developer of various zimlets, as well.

Not happy with Zimbra Desktop, still facing problems in installation and setup, I need to work more on ZD to run it successfully for all users in my organisation.

Dipesh