The default database size limit for Exchange Server 2010 Standard Edition is 1TB and virtually no limit for the Exchange Server 2010 Enterprise Edition, but theoretically, the database size limit is 16GB which of course, is not practical and recommended approach for any kind of scenario.
Microsoft recommends database size limit of 100GB per database if not using DAG, and set maximum database size limit as 2TB per mailbox database if DAG consists of minimum three copies of mailbox database.
We can edit the registry values to impose the mailbox database size limits. Open the registry and locate the below values:-
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\MSExchangeIS\<Server Name>\Private-<database GUID>
- If the Database Size Limit in GB DWORD exists for the subkey, change the value to the desired size in gigabytes.
- If the Database Size Limit in GB DWORD doesn’t exist for the subkey, create a new DWORD with that name, and then set its value to the desired size in gigabytes.
