Disable spotlight OSX Lion server and its consequences

Hello,

we are encountering huge performance issues with spotlight on OSX Lion Server (10.7.4). After every reboot or a power outage (shortly happened), it takes a long time until we can use the system again. At this time the spotlight icon indicates that spotlight is running and indexin the system.

All services are unavailable or really slow in responding to requests.

We are running Mail, iCal and Contacts on the server. Hardware is a MACPro with 4 Cores and 32GB of RAM.

Can we safely disable spotlight or are there any new problems we will run into? Maybe it is possible to disable spotlight only for the folder that holds the mailboxes, where are a lot of small files are stored.

If it is safe to disable spotlight, how can we achieve this without breaking anything on the system?

Any help or hint will be much appreciated.

Thanks in advance

Frank