I've perused the wiki and this forum looking for ideas as to how fulfill the hardware requirements for a 2000 user Zimbra Network Edition deployment.

The mandate is to look for a single server solution, which I think is somewhat realistic(maybe). What I'm missing is the max # of concurrent users anticipated to hit the application and the mailbox size limit per account. Clustering is a possibility.

For right now, I'm assuming 500 concurrent users. All of them web client users.

Two Opteron Dual core CPUs
RedHat ES 4 64-bit
4GB RAM
250GB SATA RAID1 or 300 SCSI RAID1 (RAID 0+1 might not be an option)

Any feedback is appreciated.