This evening I learned about:
- Address lists (e.g. creating lists other than the GAL; replacing the default OAB).
- Mailbox stores. It seems that a single mailbox store consists of two files, the .edb file and .stm file (MDBEF and MIME formats, respectively)...and one or more log files.
- Moving mailbox stores to different disks, and mailboxes into different stores.
In Exchange 2003 Standard w/ SP2, you can have a single mailbox store of up to 75GB. In the Enterprise version you can have up to 20 stores which, I think, can each be up to 8TB in size. Wow.
There's also something called circular logging which prevents Exchange from saving zillions of log files and thereby chewing up your disk space. The downside of enabling this is that it somehow reduces your disaster recovery options and requires that you regularly run a full backup of your stores. Of course, you can also keep logging enabled and do frequent backups & the backups will automatically delete the log files. So, there's little value in using circular logging.
The two database files, the .edb and .stm files have something to do with MAPI (i.e. "Outlook") and non-MAPI clients (i.e. everything else), but I'm not quite sure what.
Haven't figured out what an X400 address is, but one site says that you can't disable it.
Deleted items retention - it's a great feature. I've used it on two occasions to make people very happy. In one case, a user accidentally deleted her items. On the other occasion, an employee was terminated (but her user account was left enabled) and she logged in from home to delete emails via OWA. We recovered those emails, but what if the employee had known about DIRT (deleted items retention time) and what if the employee had purged those messages via OWA? We would've had to do a restore from backup...and that would've been very time-consuming ('cause so far, I've never restored an Exchange backup!). Microsoft tells how to hide the relevant command in Outlook via GP, but that won't help w/ OWA. There's a helpful post about this general topic at Experts-Exchange.