When we connected to the company's network through Remote Access Service
(RAS) or Dial-Up Networking (DUN), the RAS configuration prevented us from
accessing the client's DNS server. The DNS server did not respond to the
client's request and thus delayed Outlook's startup. After the DNS query timed
out, the client checked the NetBIOS name cache, Windows Internet Naming Service
(WINS) server, broadcast, and LMHOSTS file. To prevent this delay, we placed the
Exchange server's IP information in the client's HOSTS file.
Managing Message and Address Storage
For optimal performance, the Outlook client must efficiently access
information from the server. You can configure Outlook to access the server in
several ways. The client software communicates with the server to send and
receive messages and to access the global address list (GAL) and public folders.
You can control how often this communication takes place. Modifying
communications timing preserves network bandwidth.
You must decide where to store messages, addresses, and archive
information. You can store messages and addresses on the Exchange server
(within the Exchange database) or outside the Exchange database. Address
information within the Exchange database forms a GAL, and address information
outside the database forms a personal address book. You can use the contacts
application to store information within or outside the Exchange database.
Archive information includes old messages and meeting requests.
You maintain this information on a workstation or file server.
Messages. You configure the client to dictate where it stores messages. You can configure Outlook to keep messages in
personal folders (.pst files) or in offline storage (.ost) files. The Microsoft Outlook 97 Administrator's Guide (http://www.microsoft.com/outlook/adminguide) provides complete details about these files.
You need to understand how each mechanism affects your networking and where to store the two file types.
You can store .pst files on your workstation or server. When you use a .pst file to store your inbox messages, Outlook funnels messages from the Exchange server to the .pst file. If you maintain the file on your workstation, messages move across the network from the server to the workstation only once. You can quickly read .pst messages because no network traffic is involved. Storing .pst files on your workstation has two disadvantages: You need to use backup strategies to prevent data loss, and you need to share your hard disk if you want to access your messages from another machine. In addition, Exchange places an exclusive lock on open .pst files, so you can't access your messages from a
remote machine if your local machine uses Exchange.
If you store .pst files on a server (file share), Outlook moves messages
from the Exchange server to the .pst file. As Figure 1 shows, this procedure
requires two network transactions: one to move the message to the client and
another to move the message to the file server. When you try to read a message
in Outlook, a third network move occurs, to move the message back from the file
server to the client. Deleting a message generates additional network traffic.
You maintain .ost files on your workstation. An .ost file maintains a
synchronized copy of information from the server. If you have an inbox in the
.ost file, incoming messages move from the server to the .ost file only once.
You then work from a local message store. You specify the frequency for updating
offline storage. If network bandwidth availability is inconsistent, you can use
.ost files and synchronize events to improve performance. Offline folders
increase the availability of messages. Outlook synchronizes the .ost file with
the server, so you can maintain backups at the server, and you can retrieve
messages from any workstation with access to the Exchange server.
If you store .ost messages on a server, the messages move across the
network each time you access them. If you read messages only once and delete
them, you generate the same amount of network traffic as if you used a local
.pst file. Deleting messages without reading them (i.e., reading only the
header) reduces network traffic. Reading messages multiple times generates
excessive network traffic. Consider how you will access messages to determine
the best storage option.
Addresses. You can maintain address information on the
server (GAL) or the workstation or file server (personal address list). Each
time you attempt to send a message, you access this information.
Working offline lets you use a locally cached copy of the GAL. This cached
GAL resolves names more quickly than if you access the list over a WAN link. If
your address book changes frequently, you must download it more often to
maintain a current file.
You can maintain a personal address book (.pab) file locally on your
workstation or remotely on a file server. File server storage provides central
access if you switch machines, but it requires more network attention. Instead of using the .pab file, you can use the mailbox contacts to store personal addresses. One drawback is Outlook's inability to incorporate contact resources into distribution lists. This feature would eliminate the need for personal address books.
Archive information. Archiving messages can cause
complications. You can archive messages you stored as .pst files or messages you stored on the server. The archive file is a .pst file, so if you archive
.pst-stored messages, you move messages from one .pst file to another and thus create additional network traffic. The amount of network traffic you generate depends on where you store the archive .pst files. The default archive file location is the NT or Win95 profile path. If you use server-based profiles, the archive file follows you. Outlook copies the file as part of your profile, so your logon and logoff time increases as the file gets larger.
Outlook 98
Improperly configuring the client software can cause performance problems in Outlook and Exchange. Outlook 98 includes several enhancements. For example, many communications tasks that currently tie up the workstation are background tasks in Outlook 98, giving you more time to read and compose messages. If you haven't upgraded to Outlook 98, consider doing so.