Exchange has five key pieces. These core components are email,
folders (the basis of information sharing), scheduling, forms, and connectors.
Email
Exchange offers rich-text
email capability. You can create email messages with text in multiple fonts,
colors, and sizes. Messages can also contain in-place Object Linking and
Embedding (OLE) objects, such as Excel spreadsheets and Word documents, as
Screen A shows. Exchange provides address books to store email addresses of
recipients and information (e.g., company name, voice phone number) about them.
You can set up multiple address books to store email addresses for various
recipient groups. A convenient feature is the ability to send email to anyone
with an SMTP address. You can set up complete address books of friends, vendors,
or customers who have an Internet address and send email to them from Exchange
(although you lose some of the rich-text formatting unless the recipients are
also using Exchange or another Messaging API (MAPI) rich text-enabled client.)
Folders
Folders store information
in the database. They are containers for messages, forms, files, and other
folders. Folders appear as a hierarchical tree to users, who can easily post
information to folders and move information among folders.
The three folder types are personal, public, and mailbox. Personal folders
are for private use and are a good place to keep information you want on your
local machine or that you may need a password to access. Public folders are the
basis of information sharing. They provide public access to information, and you
can use them in groupware application development. Mailbox folders store
inbound, outbound, and server-based private mail. All these folders can have
offline versions that Exchange can synchronize with the online folders
letting you work offline and easily keep your work in synch with online objects.
(For an explanation of how to synchronize offline and online folders, see the
main article.)
Exchange stores folders in its database, which uses the client/server
model, which is optimized to speed email and groupware applications. A drawback
is that you can't read or update the Exchange database outside Exchange. No Open
Database Connectivity (ODBC) drivers or other database tools currently let
developers directly manipulate the Exchange database. However, Microsoft plans
to add the ability to manipulate the Exchange database in the next release of
Microsoft Access to let Exchange support more complex, database-centric
applications. For instance, a customer tracking system will be able to obtain
the customer's account balance from SQL Server or Access and post the balance
directly to an Exchange folder.
Exchange's replication and directory synchronization features let you store
the same information on multiple servers, significantly improving the response
time for accessing information that, for instance, may be on an Exchange server
in Europe and also on a server in the US. Replication can reduce communications
costs, because you replicate data once, and then Exchange sends only updates and
additions.
Of course, Exchange wouldn't be as much fun if you couldn't do the opposite
of replication and configure folders for cross-server access, but you can. The
Exchange administrator can designate public folder affinity, letting users
connect to folders outside their designated site.
Naturally, Microsoft has created hooks from Microsoft Office applications to
Exchange. For example, you must have Microsoft Office version 7.0a to post
documents directly to a public folder on Exchange. Also, your personal email
address book from Exchange is available on the Word toolbar. You can email a
document to another user by selecting Send from the File menu of an Office
application, or you can route a document to another user or users by selecting
Add Routing Slip, from the File menu. Routing lets you choose how to send the
document to peoplesequentially or all at onceand lets you control
the revision capability along the route. You can put any Office document in an
Exchange folder, and you can use the properties of the document (e.g., the
author, the revision date, or the cell of an Excel spreadsheet) in a view that
you create to look at the folder (i.e., you can use the properties to search for
documents in the folder).
Scheduling
Exchange uses Microsoft
Schedule+ 7.0a to support scheduling. Schedule+ is an easy-to-use program that
you access from the Exchange client. Schedule+ lets you create and maintain
schedules for people, teams, and tasks. The Meeting Wizard leads you through
choices for who needs to attend; what resources (e.g., audio/visual equipment,
meeting rooms, squirt guns) are necessary; and the meeting's location, time, and
duration. The wizard then verifies the schedules of the required people and
resources and the optional people and resources, and determines whether your
meeting time is possible. If so, the wizard sends email notices to the attendees
and updates their personal schedule. Schedule+ is best when you can get everyone
to use it, but it's also great for individuals.
Forms
Exchange forms are simply
electronic versions of the paper forms we all use each day to structure data for
fast and efficient viewing. With forms, you can request vacation days, report
travel-expense information, track phone messages, and so on. Unlike paper forms,
however, these forms arrive via email through Exchange, and they can contain all
sorts of other objects (e.g., OLE objects) and information. Forms can send a
message or post a message to a folder. If you post forms to a public folder, you
can view and search them for content. Exchange forms are a convenient and
easy-to-use front end for the Exchange database.
You can create custom forms that look exactly like your paper forms, and
Exchange can route these forms throughout your company. You create Exchange
forms with the EFD, which ships with Exchange. The EFD contains VB for Microsoft
Exchange Server Version 4.0. VB generates source code that you compile to
produce the form. With VB 4.0's 16-bit version, you can extend forms you create
with the EFD.
Forms are the vehicle for extending Exchange. I think we will see
significant application development based on Exchange forms, and third-party
developers will create entire applications and tools to support Exchange.
Connectors
Connectors let Exchange
communicate with other Exchange and non-Exchange systems over many different
transports, protocols, and mail systems. Exchange supports dynamic folder
replication between Exchange servers. This capability is useful, for instance,
if you have a large company with multiple Exchange servers. Replicating folders
across servers is faster and more secure than granting access rights to server
folders.
Exchange uses several connector types. The site connector requires a
permanent LAN connection and uses remote procedure call to connect Exchange
servers within the same site or LAN. A site connector is the fastest connection
possible because you have no protocols to negotiate between servers.
The X.400 connector can connect Exchange servers to each other or to
another X.400-compliant mail system. An X.400 connector can use a public X.400
connection that long distance telephone carriers provide.
The Dynamic Remote Access Service (DRAS) connector provides dial-up support
between Exchange servers. A DRAS connection is useful for low- to midband
connections where the phone company connects servers through modems. You can
specify the connection interval. For instance, you can connect each hour during
the work day and only twice during nonworking hours.
The Microsoft Mail connector links Exchange and Microsoft Mail. This
connector lets you move messages back and forth between Exchange and Microsoft
Mail and lets you share Schedule+ Free/Busy schedule information to ease
migration. (For an analysis of the Microsoft Mail connector, see Spyros
Sakellariadis, "Migrating MS Mail to Exchange," April 1996.)
The Internet Mail connector links Exchange with the Internet and any
SMTP-based system. This connector lets you send and receive Internet email from
Exchange. Soon Microsoft and third-party vendors will introduce several gateways
to provide access to SNADS and other data stores.