If you do not feel comfortable editing the registry, do not attempt these instructions.
Prior to Microsoft Exchange Server 2003 Service Pack 2 (SP2), there was no method to configure database size limits for Exchange Server 2003. Exchange Server 2003 SP2 introduces the following new features:
For the Standard Edition, the default configured database size limit will now be 18 GB, a 2 GB addition to the previous limit, with a new maximum size of 75 GB.
For the Enterprise Edition, there is no default configured database size limit, and no software set maximum size.
Both versions of Exchange Server 2003 with SP2 have the ability to configure a limit, a warning threshold, and a warning interval set through registry keys.
Size check done against the database now uses logical database size. Empty or white space in the database does not count against the configured database size limit; therefore, no offline defragmenting is required for recovery exceeding the configured or licensed database limits.
Limit checks, done at regular intervals, are now controlled by the store process instead of JET. The default time interval is 24 hours and this interval is configurable through the registry.
1. Open regedit locate the following registry
HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\MSExchangeIS\Server name\Private-Mailbox Store GUID
2. Create a new DWORD entry called “Database Size Limit in Gb”
And enter the new limit you desire for your exchange 2003 server; there is size limitation between versions
Exchange 2003 Standard SP2: 1-75GB
Exchange 2003 Enterprise SP2: 1-8000GB
3. Create a new DWORD entry called “Database Size Buffer in Percentage”
Optional, typically set to 10(10%); and event viewer will show the event when the database close to the size limit.
4. Create a new DWORD entry called “Database Size Check Start Time in Hours From Midnight”
Optional, 0-23 which specific when do you want the exchange server check for the database size. Example: 3 (which mean 3 hours after midnight which is 3 AM).
*You will need to stop and restart the exchange services for that to work.