I had originally had our test set up on Ubuntu 6.06 with NE, I tested 8.04 with FOSS as well. My rep at Zimbra was able to get us an extension, so it's back to NE with Ubuntu 6.06 and migrate to RHEL with NE once I have funding for my new server.
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Culley
Mail | Dell 2950III | 2x Quad Core 5420 | 8gb RAM | 6x 146gb SAS RAID 0+1 | Red Hat 5.3 | Zimbra 6.0.10 Network Edition
Test | VMware ESXi Whitebox | Phenom II Black 3.2ghz | 12gb RAM | 6x 1tb SATA RAID 0+1 | CentOS 5.4 | FOSS, Not in use now |