So you've implemented Exchange 2003 and installed it with service pack 2. Your database grows up to 20 GB from all that migration suddenly the Information Store stops with an error. Well, don't panic.
In Microsoft Exchange 5.5 until 2003 standard editions , the database logical store cannot reach more than 16GB otherwise the information store will stop gracefully. There's an allowance given by Microsoft to increase this limit 1GB more until you've cleaned up the database size and make it smaller than 16 GB. Now with SP2 on Exchange 2003, the limit is increased by default to 18GB. But they said SP2 can grow up to 75GB..?
Yes, this is possible but you need to set it through a registry key and specify the size of your database.
Here's how and where ...http://support.microsoft.com/kb/912375/en-us
Happy bloating your mailboxes!