Got a question about Exchange 2010 and the Database size limit:
The default database size limit for Exchange 2010 Standard Edition is 1024 gigabytes (GB), which equals 1 TB.
There is no default database size limit for the Exchange 2010 Enterprise Edition.
The Exchange store checks any database size limits periodically and dismounts a database when the size limit is reached. You can modify the database size limit by adding or changing a value in the registry.
Remember that SBS 2011 has Exchange 2010 Standard Edition, so its default would be 1 TB.
Need to change it from 1 TB; you can use Registry Editor to modify a database size limit in Microsoft Exchange Server 2010:
If you change the size limit of your Exchange databases, you may want to evaluate your Exchange database backup and restore plan. Specifically, if you increase the size limit of the Exchange databases, test your backup and recovery operations using the new database size limits to make sure that you can still meet your service level agreements (SLAs).
Get-MailboxDatabase -Identity "<database name>" | Format-Table Name, GUID
For more information about managing databases, see Managing Mailbox Databases. To learn more about Registry Editor, see Registry Editor overview.