We recently had an "outage" - users unable to access Zimbra. Their browsers would get the "page not found" errors. The Zimbra admin gui was fine, ssh to the server was fine, mail was still coming in (mail.log) - so which services should we start checking to see where the issue is?

Our resolution this time was to do a shutdown -r and Zimbra came back up just fine and users were able to get their email. Next time we'd like to know where to look and if it's restarting a service or something of that sort, go that route.

Thx for any advice.