10 Tips for Taking Exchange on the Road

I do a good share of my work on the road—last year, I worked more than 100 days in sites around the world. Wherever I am, I need to process the hundreds of messages that arrive in my mailbox every day, so I especially need good offline functionality. I've found that the combination of the Microsoft Exchange Server and Outlook client delivers what I need.

In Exchange, working offline means that you can use the client when you aren't connected to an Exchange server. You can configure server-based folders—the Inbox, Outbox, Sent Items, and Deleted Items—for offline use. Then you can dial in to your network and work remotely or synchronize your offline folders with the folders on the server. Based on my experience over the past two years, I've compiled some tips for working offline effectively.

Tip 1: Set Up OST, PST, PAB, and OAB
Four types of files are important for working offline:

• The offline store (OST), which contains slave replicas of selected server-based folders—replicas of the Inbox, Outbox, and Sent Items folders and the other special folders (Calendar, Tasks, Journal, and so on) that Outlook maintains. You can have only one OST.
• Personal stores (PSTs), which are local file stores that extend the overall storage capacity available to users. A client can open multiple personal stores during a session. Exchange doesn't replicate the folders in personal stores to or from server folders, as it does with an OST. Personal stores are optional for working offline.
• The personal address book (PAB), which holds the email addresses of people you correspond with. Entries in Outlook's Contacts folder can also have email addresses that you can use to address messages.
• The offline address book (OAB), which holds email addresses from the Exchange Directory. Exchange generates the default OAB from the Global Address List, but Exchange can generate different OABs based on Address Book Views. You can, for instance, have an OAB that contains the names only of people in a certain country or department. Outlook treats the OAB as one logical file but holds the data in several separate .oab files in the Windows directory. This arrangement can be confusing for users who roam from PC to PC, because they can easily forget to copy a set of .oab files to take between PCs. Exchange usually generates the OAB every night.

By default, Exchange stores the OST, PST, and PAB in the Windows directory. I recommend that you create another directory (e.g., C:\<username>\exchange) for these files. Using a different directory establishes a clear separation between Windows and application data and lets you maintain privacy more easily. I also recommend changing the name of your OST from the default (exchange.ost) to something more personal, such as <username>.ost, so you can more easily associate files with particular users. You can't move the .oab files outside the Windows directory. . . .