New server for up to 10 users,
2x160Gb HDD SATA (software raid1)
Zimbra 4.5 (latest from open source site)
Server starts up okay, no errors in logs, starts Zimbra up, works without any problems for 2-3 hours and then the weird stuff starts happening:
1. Zimbra services become unavailable, no mail, no http interface
2. several minutes later system restarts.
overheating checked and rechecked - the machine is like a fridge.
couldn't find anything in system logs