Serivce Pack 2 for Exchange Server 2003 introduced some new configurable settings for information store database limits. These limits used to be hard coded depending on the version of Exchange you were using. Standard Edition was capped at 16GB and Enterprise Edition was capped at 8TB (which is the largest an Exchange Jet database can be). After applying SP2, administrators can now set arbitrary limits to the sizes of their information stores. Standard Edition users are still limited to one private and one public store, but can set both of them to a maximum size of 75GB! It is not configured this way out of the box, however!
By default, post-SP2 Standard Edition servers have their information stores set to a maximum size of 18GB with a 10arning threshold. This warning percentage replaces the "dies at 16GB, then set a registry tweak to give you 1GB more temporarily" way of dealing with the database cap previously. The new way warns administrators via the event log 24 hours in advance that the warning threshold has been reached. If no action is taken in that time period, the information store gracefully shuts down. When everybody at your company cries that their email doesn't work, you can turn it back on for another 24 hours and clean up the space in the mean time. However, if your store reaches it's hard limit, you are back to the old "registry tweak to get one more GB" scenario. But at least you have new options and more time now.
If you have the hard drive space to increase your information store from 18GB to 75GB (or anything inbetween) you have to set a few registry values to make these changes.
I was bored, so I made a tool to do this for you. Keep in mind that it tinkers with Information Store registry keys, so use it with caution and test it first, as you should any new piece of software before deploying it to production servers!!
Exchange 2003 Enterprise Edition users might find this useful too, should they want to cap their databases to fit within the constraints of their hard drive and create warning thresholds to keep it from potentially corrupting the database by reaching that limit of the hard drive. Graceful shutdowns are your friend! By default, Enterprise Edition has no limit set (other than the 8TB hard limit which is constrained by the fact that Exchange just can't handle a single information store larger than that).
Let me know if you use this tool!
Here is the link...