Brian Valentine, Microsoft General Manager, Exchange Group 1993
This has been Microsoft's compelling vision for Exchange since its conception in 1993.
But what exactly is Exchange? Microsoft Exchange Server is a messaging product for businesses, integrating e-mail, group scheduling, electronic forms, and common groupware applications in one product that can be easily managed via a single administrator program. Exchange facilitates collaboration within companies so teams can share the latest information obtained, internally via intranets and externally from the Internet and newsgroups. This messaging product also enables managers to schedule meetings with several people and manage resources through a common interface. Departments can set up information repositories (solution databases) for reference and discussion. Companies can create virtual knowledge bases with their business partners using an extranet. In short, Microsoft Exchange Server 5.5 is designed to help you communicate and collaborate with anyone, anywhere, anytime--easily.
This chapter provides an overview of Exchange 5.5, its new features on both the client and server side, and its positioning as an enterprise-wide messaging system.
Electronic mail has been in existence for many years. The original electronic mail systems--including PROFS, SYSM, and Memo--resided on UNIX-based host computers or IBM mainframes. The single host, whether it was a mainframe or a minicomputer, was a centralized solution. These electronic mail systems, many of which are still running today, are text-based and provide enterprise-wide messaging.
PCs began to grow in capability and popularity, however. As their acceptance became widespread, their cost began to drop, prompting more purchases, especially in corporate America. More and more computing was taking place at the desktop instead of within a centralized machine. The PCs began communicating with each other via small workgroups and Local Area Networks (LANs), extending their reach. It wasn't long before LAN-based messaging took root and grew within the same company walls that housed the mainframe messaging solution.
LAN-based or shared-file messaging occurs when the client desktop initiates and controls all messaging activity. When a user composes and sends a message, the client software sends the message to the server or post office into a specific directory or file (or mailbox). A recipient retrieves his messages by accessing his specific mailbox on the server. The server is passive and primarily stores messages (see Figure 1.1).
FIG. 1.1 Message flow using shared-file messaging.
At the time, there were advantages to this architecture:
But there were weaknesses as well:
To address these weaknesses, client/server messaging was designed to distribute messaging processing between the client and server, enabling each system to focus on tasks best suited for its role. When a user composes and sends a message, for example, the server places the message in the appropriate directory or forwards it to another server. The recipient receives the message without constantly polling the server. Microsoft Exchange was developed using client/server messaging architecture (see Figure 1.2).
Client/server messaging improves upon shared-file messaging in the following areas:
FIG. 1.2 Message flow using client/server messaging.
The Exchange client component on the recipient's PC receives information that the creator or source "pushes" to it. Exchange goes beyond the push model by providing a shared repo-sitory--Public Folders--for storing information that is on call for the user. This repository enables users to "pull" information down to their workstations when they need that information. Because it provides both push and pull technology, Exchange does not constrain corporations with the distribution mechanism. Exchange provides a complete solution.
Now that you have a historical perspective of messaging, it's time to examine Exchange's key features and how they can meet your messaging needs.
You should become familiar with some key concepts and definitions that are used throughout this chapter:
The concept of the universal inbox has been around for years, but the capability to deliver such a product is revolutionary. Microsoft learned from its research that users want an integrated desktop environment to improve their organization and control of daily activities. A universal inbox interface makes it easy to organize personal, public (shared), or online information all in one place. A user now can view information in a variety of ways, and easily find information anywhere on the desktop. Future BackOffice products and especially Windows 98 will seek to leverage this model.
The key to the Exchange inbox is the fact that Microsoft provides the gateway to all your company information. Third-party software developers are pursuing business opportunities on this foundation by building their applications on top of this technology; these applications appear as folders. The vision is to provide one standard location and interface for accessing information, regardless of the information's format. Solutions are available for integrating voice-mail systems into Exchange, for example. If you have a multimedia PC with an integrated sound system, you can access your e-mail as well as voice mail, or dial in from a telephone to "hear" your e-mail along with your voice mail.
The Exchange Outlook client interface embodies the concept of the universal inbox by providing a consistent look and feel across all the supported platforms and released versions. Exchange 5.5 now presents a "flavor" of the Outlook client for each operating system that connects to Exchange (Windows 95 and Windows NT, Windows 3.x, Macintosh, DOS, and via the Internet).
The client also enables you to place filing, printing, viewing, deleting, and other functions on convenient button bars. These button bars keep the desktop uncluttered and yet enable the desktop to contain many pieces of information.
When you use the Exchange Outlook client, you have control of several folders that are displayed from the Microsoft Exchange root folder tree. These folders are very similar in layout to Windows Explorer, which ships with Windows 95 and Windows NT 4.0, and to the File Manager in Windows 3.1 and Windows NT 3.x.
The three main folder types are described here:
As mentioned earlier in this chapter, Exchange enables users to organize information according to their taste. Exchange provides some features to make this process much easier. Those features are described in the following paragraphs.
A view is simply a way to order information. Information can be sorted by author, keyword, date, or subject.
Two kinds of views are available: folder views and common views. Folder views order information in individual folders. If you have a private folder called Peter that contains all mail from Peter, you can define a view that sorts all the objects in the folder by date. Then you could change the view for the folder to include a secondary sort criterion, such as subject. The data then would conform to the view only in that folder. Common views are views that can be applied to any folder. You can define a view called Date and apply it to many folders at the same time.
In addition to providing many predefined views, Exchange is also flexible enough to enable you to create views, including custom fields from forms and even Microsoft Office documents like Word or Excel. If a public folder has a database element that contains a Boolean logical (Y or N) field, for example, you can create a view that sorts all the Yes records before all the No records.
Rules are a set of conditions that when met, organize incoming messages. For example, you can establish a rule dictating that if Sender = My Manager, to file the message in a folder called Urgent, and play a sound.
Auto-Assistants enable you to have rules in effect even when you aren't logged on. If you go away on vacation, for instance, you can have a generic message auto-replying to all messages saying you'll return in one week. If the message contains a certain keyword in the subject, you could have your mail forwarded to someone else to take care of it or to another e-mail account where you can review it.
The Find feature is a powerful search engine that enables you to specify criteria for finding items in any or all of your folders. This feature is extremely useful when you remember a subject or a keyword but can't remember who sent the message or what the actual content was. You can have the Find feature look for the message in all your folders.
The Find feature runs in the background and is treated like any other running program, enabling you to continue working while the search is under way.
When you are presented with the objects that meet the specified criteria, any action you take on those objects takes effect in the actual folders the objects reside in. For example, you can use the Find feature to retrieve all messages 30 or more days old. As messages appear in the Find window, you can select all of them, and click the Delete button. They will all be removed from their respective folders.
Adding a third-party search index tool to your Outlook client can make searching even more powerful and much quicker. Options are available for search indexing on the Exchange server as well.
With the proper permissions, you can view someone else's calendar or schedule to find the best time to schedule a meeting. The Calendar function, once a separate function using a Schedule+ client, is now completely integrated into one client called Outlook. Read on for more information.
Exchange provides the Outlook Forms Designer to extend the functionality of Exchange. Exchange now becomes a platform product upon which business messaging solutions like document databases and groupware are built. The Outlook Forms Designer is targeted for the non-developer, but experienced developers can use their Visual Basic expertise to take Exchange's forms to the next level.
Exchange provides a wizard to assist developers in converting Outlook forms into HTML format. A single seat license for Microsoft Visual InterDev is also provided to further customize and enhance the HTML code for usage with the Active Server Pages components of Exchange and Microsoft's Internet Information Server.
Outlook Forms Designer The Forms Designer enables the administrator (or any other user, if granted permission) to create custom forms that can replace paper forms. Most consulting companies have standard forms for consultants to describe their backgrounds for use in proposals. Why not create this form online, store it in a public folder, and allow the consultant to fill it out on screen and send it to you for processing? You also can create a Visual Basic program to take the data off the form and store it in an Access, FoxPro, or SQL Server database for later retrieval and manipulation. With the enhancements to the Information Store of Exchange 5.5, the data could continue to be stored in Exchange.
Imagine using an electronic form to requisition office supplies. You could quickly tally the total cost of office supplies for a month by using OLE to create an Excel table from the Exchange data.
Forms can be stored in three places: the Enterprise Forms Registry, the Personal Forms Registry, and the Folder Forms Registry. The following list describes these elements:
By providing a simple graphical user interface, the Outlook Forms Designer enables users to create forms without the need for complex programming.
It may be difficult to believe, but the Outlook Forms Designer is a front end to Visual Basic. Simply drawing the fields in the form sends the proper commands to Visual Basic to create the executable form. You do not have to be a Visual Basic guru to create forms and to extend the functionality of Exchange beyond the transfer of messages.
Savvy Visual Basic and C++ developers can integrate their own custom codes to extend Outlook forms to do amazing things as noted in the following sections.
CAUTION: With Outlook and Exchange 5.5, the Macintosh Outlook Client can only support the electronic forms that have been specially customized for use by the Macintosh client of Exchange because the forms are based on Visual Basic components. Forms that are not usable by the Macintosh client will display a special symbol indicating this lack of compatibility.
Custom Application Programming with MAPI Exchange Client applications aren't limited to those that ship with Exchange. Because Exchange is based on the Messaging Application Programming Interface (MAPI), you can design applications that take advantage of Exchange's underlying folder architecture by accessing data via MAPI.
Custom applications can use MAPI to perform such tasks as opening a public folder and dropping in data, searching data, deleting items, and examining the contents of folders. All actions are subject to the permission that the application has for any given object. If the program is running with the permissions of a user who doesn't have the ability to delete data, the application cannot delete any data.
MAPI also can be used to add functionality to a form created with the Outlook Forms Designer. You can write a program that takes data from a custom form, imports that data into Excel, performs some calculations, sends the compiled results to the user in an e-mail message, and then faxes a copy to another recipient.
Exchange enables the user to post information on an electronic bulletin board (public folder). For example, marketing representatives can track customer accounts from a shared contact-management database and access product information from a reference library. With Outlook, creating the folder applications can be very simple.
The Internet Mail Connector (IMC) that was first introduced in Exchange 4.0 has continued to grow in functions and protocol support. Exchange 5.0 saw the renaming of the IMC to reflect what it had evolved into--a group of "services" now called the Internet Mail Service (IMS). Included here are the SMTP mail gateway between Exchange and the Internet for sending and receiving, as well as POP3 support for standard POP-based mail clients such as Eudora or the new Outlook Express client. IMAP4 support has been added in Exchange 5.5 as a dramatically enhanced upgrade to the POP standard. Web Browser support for access to a user's mailbox, calendar, and public folders is available when the HTTP protocol is configured with Active Server Pages and IIS. Any browser that supports frames can be used to log on and view dynamic HTML representations of a mailbox's content. When accessing in this method, the browser is using the Outlook Web Access components installed on the Exchange server.
To facilitate easy directory access for these POP/IMAP4 and browser clients, Lightweight Directory Access Protocol (LDAP) is available. Exchange 5.5 is supporting the soon-to-be- published LDAPv3 standard by offering a full set of 16 commands for LDAP usage, including reads, writes, and referrals to other LDAP servers. NNTP newsfeeds and function are supported and enhanced in 5.5, allowing for more options to configure NNTP replication to and from Internet NNTP newsfeeds.
Finally, a rich environment for interfacing Microsoft's Internet Information Server with Exchange to enable publishing and interaction with public folders within Exchange has been added, collectively called Active Server Components. By usingCollaboration Data Objects (formerly called Active Messaging), you can easily publish Exchange public folder data and custom forms to the Web. All of these help integrate a company's messaging enterprise into a much larger messaging system--the Internet. These are described in more detail later in the chapter.
Exchange with Outlook clients enables users to work offline. Users can use the Exchange Outlook 32- and 16-bit clients from their PCs via remote network access (dial-up connections) or while they are disconnected from the network. Exchange is designed to use RPC calls, which, when coupled with dial-up connections, are designed to sense the line speed and optimize performance.
Exchange can be used over asynchronous connections, including ISDN, PPP, PPTP, SLIP, X.25, and regular modem connections. This form of Exchange connectivity holds true for client-to-server connections as well as server-to-server connections. Additionally, security can be implemented when using NT's Remote Access Services for dial-back and challenged dial-in via NT C2 security.
Microsoft Exchange Server administration is performed from a single tool capable of connecting to every site and server in your Exchange organization--Exchange Administrator. This program gives the server administrator a graphical representation of all directory objects in any site for which he or she has permission.
Exchange Administrator is used to define the hierarchical structure of the organization's messaging infrastructure. You can define and set properties for elements such as connections to other mail systems, recipients, servers, and addressing templates.
The advantage of centralized administration is that it enables you to see the entire object tree or hierarchy of information and make any addition, move, or change in an easy, straightforward manner, regardless of the location of the server. If your company merges with another company that has a Microsoft Mail messaging infrastructure in place, for example, the Exchange Administrator can add the Microsoft Mail connector, and connectivity would be available to all specified users on all specified servers. The convenience of adding functionality from a central console is apparent, in this case, in size of enterprise.
If decentralized administration is desired, you can open multiple administrative sessions and set permissions to the various objects and components of Exchange to allow different administrators to modify and control these different features. In an extremely large Exchange organization, setting specific permissions and spreading out Exchange administration responsibilities can be very advantageous.
Many companies don't consider a messaging system to be a mission-critical application. However, the reality is that e-mail is one of the few applications on everyone's desktop and that most everyone relies on. To keep your users happy, Exchange offers a number of tools and features to prevent Exchange from becoming "unavailable" (see Table 1.1).
| Tool/Feature | Function |
| Link Monitor | Link Monitor watches for successful message connections between two points in an Exchange organization. They also can be configured to test connections to foreign messaging systems. Use this tool to determine if an Exchange server or network link is experiencing problems. Naturally, alerts are given if the link is unresponsive. |
| Server Manager | Server Manager tells you whether any of a server's services has stopped and enables you to restart those services remotely, even across a wide-area network (WAN) or active telephone link. As with the Link Monitor, alerts are available to notify administrators of server problems. |
| Performance Monitor | NT's Performance Monitor (PerfMon) enables you to monitor statistics for most software and hardware components (processor utilization, available memory). Installing Exchange adds several specific counters for detailed Exchange diagnostic work. PerfMon can be set up to page you if certain thresholds are exceeded, such as a message queue that has exceeded 1,000 messages or disk space that has dropped below a preset threshold. |
| Event Viewer | Event Viewer comes with Windows NT; it logs system, security, and application events (including Exchange). Not all events are errors. For example, an event is logged when Exchange finishes recalculating the routing table. Use Event Viewer to determine the source of errors from Exchange. |
| SNMP | RFC 1566 MADMAN MIB is supported in Exchange 5.5 to allow for monitoring of the mail connection elements of Exchange from SNMP monitoring tools such as HP OpenView. |
| Intelligent Rerouting | Exchange can have multiple connectors between servers to provide fault tolerance. If one connection goes down, Exchange automatically reroutes traffic through another connection. Exchange 5.5 gives the administrator the option to force Exchange to look only at route costs when considering how and when to reroute messages, making the "dynamic" element more predictable. |
| Directory Service (DS) | Because the DS is like Exchange's telephone book, it must be protected. Not only is the DS replicated to every server in a site and synchronized, it can recover from a catastrophic failure through the rollback features of the transacted database and distributed tree architecture. |
| Fault-Tolerant Store | Exchange uses a transaction-based logging system to ensure users never lose a message from the Information Store (IS). All transactions are written to a transaction log, then committed to the Store. In the event of a power failure, all transactions can be completed using the transaction log. |
| Backup | When installing Exchange, you enhance the built-in NT backup provided as a tool of NT Server, enabling the backup of open Exchange files. Other more capable Exchange-aware third-party backup tools are available. |
| Auditing | NT's auditing enables an administrator to log and view the full spectrum of security events, such as someone attempting to use the Administrator ID or attempting to delete several mailboxes. |
As more people depend on e-mail for communication, the need for secure messaging grows. Exchange offers three levels of security and manages the user accounts and the Information Store activity. Exchange also hooks into the NT's C2 level security and incorporates several additional security mechanisms to protect the data stored on the server, the data on the client PC, and data in transit.
Exchange provides for RSA digital key encryption, which is used to authenticate the user who is sending the message. When a user "signs" a message, the signature guarantees that the name associated with the message is the actual name of the author.
In addition to the digital signature, you can enable digital encryption of messages. Exchange uses an algorithm called CAST developed by Northern Telecom. Security is discussed further in Chapter 27, "Exchange Security."
Exchange offers a wide variety of connectivity features. Through its connectors and third-party gateways, Exchange enables users to exchange mail with external e-mail systems that use different messaging protocols, such as host-based mail systems using SNA, Internet mail systems using SMTP, and foreign host systems using X.400. Mail can also be exchanged between Exchange sites using TCP/IP, IPX, or NetBEUI. Exchange offers the following connectors:
In addition to the aforementioned connectors, third-party gateways for Exchange extend your reach. Exchange supports its own gateways and Microsoft Mail (PC) gateways as well. The following are just a few gateways that are available for Exchange from third parties:
Regardless of the origin of a message, all message objects in a user's mailbox look exactly the same. Additionally, any installed connectors or gateways are transparent to the user. That fact is a key advantage of Exchange. A user's data is collected and consistently formatted in a universal inbox.
Like incoming mail, outgoing mail is routed through connectors and gateways that are transparent to the user. The administrator creates custom recipients that reside in address books alongside conventional Exchange recipients.
When a connector is installed to enable communication to a Microsoft Mail post office, for example, Exchange clients can immediately send and receive mail by addressing the message to the MS Mail user the same way they do when they send a message to another Exchange user. When Kent's boss says, "Please send a message to Dan Gardner at the Dallas office," Kent can start up his Exchange client and send the message directly to Dan Gardner, because Dan's name is in Kent's address book in Exchange. Likewise, because Kent shows up in the MS Mail post office and Dan's address book, Dan easily can send Kent a reply.
When a connector or gateway solution isn't available, or there is no need for coexistence because the old mail system will be retired, Exchange provides tools that are used to move data from one system to another:
As you can see, Exchange provides the flexibility to be suitable for large and small environments and the adaptability to import data from other messaging programs, and integration with heterogeneous environments. Exchange also provides messaging solutions for any size organization with any combination of existing mail systems.
Another use of messaging is Electronic Data Interchange (EDI). Most corporations use EDI applications to exchange messages that contain information about orders, sales, and inventory.
Third parties provide support for financial transactions via Exchange. Microsoft's intent is to provide support for EDI domestically (with X.12) and internationally (with EDIfac). Exchange does not provide native X.435 support, but support in MAPI will provide X.435 functionality in the client.
Exchange provides a rich architecture for use in EDI transactions. Together with the integration of Microsoft SQL Server, Microsoft Transactions Server, and other Microsoft application environments, Exchange proves to be a very solid, useful, and cost-effective EDI solution.
Additional MAPI options are available to integrate Exchange and its powerful messaging system with your Internet Commerce applications, using Microsoft Site Server and related Internet technologies.
Third-party products from Right Fax, OMTOOL, Fenestrae, Cheyenne, and many others provide a gateway for DID-supported fax boards, such as Brooktrout or GammaFax Boards. Faxes can be sent to and received from a central location and routed to and from the Exchange client. This process eliminates the need to provide individual modems and phone lines at users' desktops or to print materials and walk them to a manual fax machine. Significant cost savings can result from reduced mailroom overhead and in overall reduced time for delivery. Administration of the fax solution can usually be accomplished from the Exchange Administrator tool to further reduce system administration effort.
Microsoft also supports its own fax gateway product for MS Mail 3.x. Moreover, the Exchange Outlook client for Windows 95 and Windows NT 4.0 can use the Microsoft Fax software, which is bundled with these operating systems. This way, a user can use existing aliases and contact lists in the local directory to send e-mail and faxes from one location.
Several products are available to integrate and unify electronic mail messaging and voice mail systems into a single architecture. Octel, the leader in voice mail solutions, has invested heavily in a product known as Unified Messenger that, once installed into an Exchange site, can actually replace a traditional voice mail system, if desired, with a completely PC-based solution. Benefits of such a system include the following:
Workflow The "workflow" concept seeks to establish strict steps for a defined business process, with limited or rules-based choices presented to users. Exchange applications with workflow go beyond forms routing, and address several workflow-application issues, such as status tracking, work management, deadline management, ad-hoc initiation of workflow processes, negotiation of dates, and autonomous reassignment of work.
Workflow can be defined in two basic approaches: serial routing and rule-based workflow. Exchange offers serial routing functionality via the Messaging Application Programming Interface. A simple example of this is the creation of a document in Microsoft Office with a routing slip attached to it. Exchange takes a modular approach to rule-based workflow, providing interfaces to enable workflow developers to design solutions that run with their database engines, performing data lookups and pulls or pushes.
Exchange is an ideal platform for workflow applications because of its MAPI foundation, directory services, and Information Store. New in Exchange 5.5 is the ability to set up scripts on the Exchange server itself to be launched on a scheduled basis or upon various triggers defined by the developer.
Several third parties have developed components that can be added to Exchange to simplify the building of complex workflow applications. Leaders in this area are KeyFile (with their product KeyFlow) and Action Technologies.
Imaging Imaging expands the capability to support multiple file types and provides a strong mechanism for reading, distributing, and annotating information. In the Exchange environment, you can integrate at the information viewer level in order to access public folder data objects from the client. With Object Linking and Embedding (OLE) support, you can drag and drop the actual image into the message. On the server, images are stored as objects in the Information Store.
Document Management Document management (also referred to as document imaging) consists of scanning documents into a system, archiving the images, and creating full-text indexes of the content. Document management now extends into the realm of multimedia and OLE objects.
Front Office Technologies offers a tightly integrated solution built on NT, Exchange, and numerous bleeding-edge Microsoft technologies to offer document- and information-management functions that not only handle document management and archiving from a traditional PC DOCS or SAROS perspective, but also add several new twists to use the replication, security, and administration features of Exchange. Information gathering from the Internet and a "personal briefing" search-and-update agent greatly enhance the capability of Front Office to act as much more than a document-management system.
Now that you have an overview of Exchange's features, you should learn about the specific changes and new additions in Exchange 5.5.
Outlook, based on the Universal Inbox, promotes not only communication (via e-mail_ within your enterprise), but also collaboration throughout your corporation and the Internet.
A 32-bit-only version of the Outlook client was introduced for use with Exchange 4.0 and 5.0 servers in October 1996. With Exchange 5.5, the Outlook interface is made available in a 16-bit variety for older Windows 3.x clients such as Windows 3.1 and Windows for Workgroups 3.11. A Macintosh and limited DOS flavor is being tested and is expected shortly after Exchange 5.5 ships. The Web Browser interface, making use of HTTP and dynamic HTML, also takes on the look of Outlook and is referred to as the Outlook Web Access client. The new Outlook Express client available with Microsoft Internet Explorer offers POP3 and IMAP4 support when connected to Exchange 5.5 and other supported standard servers.
The 32-bit version of Outlook is available with Exchange Server as a stand-alone product, and as a component of Office97. Outlook interoperates with Microsoft Mail, older Microsoft Exchange clients, Schedule+ 7.0, third party support cc:Mail, Lotus Notes, and a list of other messaging systems, offering companies the choice to deploy a single client interface as the right client for their enterprises.
Outlook's basic philosophy builds on Bill Gates's vision of "information at your fingertips." Today, most people experience information overload, especially with the popularity of the Internet. The quantity of information isn't necessarily the problem, but organizing it so you can find what you need is a challenge. Microsoft found that most people wanted a more integrated desktop. The company started meeting this need soon after, offering users the ability with Windows 3.0 to cut and paste a graph from DOS-based Lotus into WordPerfect 4.1.
Then, Office 4.2 was developed to work as one integrated application suite. As the Office suite evolves, Microsoft extends the original vision of organizing information. Outlook gives the Office user the ability to manage several types of information, including e-mail, calendars, contacts, tasks and to-do lists, documents or files on the hard drive, web links, voice mail, faxes, and more. Outlook also helps users share information by means of public folders on the Exchange server, electronic forms, and Internet connectivity (newsgroups). Listed below are key features in Outlook. For more information, look ahead to the following chapters: Chapter 29, "Installing and Configuring Outlook," Chapter 30, "Using Outlook," and Chapter 31, "Using Advanced Outlook Features."
Views Outlook enables users to arrange information any way they want to see it. Outlook by default supports five types of views: Table, Calendar, Card, Icon, and Timeline. Users can customize these into an unlimited number of personal or shared views. Table, Calendar, and Icon views are probably familiar to most users. The Card view resembles a list of business cards or index cards that concisely displays key information, and the Timeline view arranges items chronologically on a horizontal time line.
WWW Access Access your e-mail through HTTP over the World Wide Web. A browser such as Internet Explorer can retrieve e-mail and peruse server-based public folders via the Internet. Now, the user has more freedom to choose which operating system and platform (Internet Explorer for UNIX variants) is best suited for them. Microsoft has included calendar and scheduling into the latest incarnation of the web interface, called Outlook Web Access (OWA).
Full MAPI Client Outlook is a full MAPI client application, so it can work with all e-mail systems that support MAPI. Outlook includes drivers for Microsoft Mail, Microsoft Fax, Microsoft Exchange Server, Internet Mail (SMTP/POP3/IMAP4), The Microsoft Network (MSN), and Lotus cc:Mail. Additional third-party MAPI drivers are either available or under development for America Online, CompuServe, Lotus Notes, Novell GroupWise, Hewlett-Packard OpenMail, and Digital's All-in-One.
Backward Compatibility Outlook coexists with the original Microsoft Exchange client and Schedule+ 7.0 and works with earlier versions of Microsoft Mail, Microsoft Exchange client, or Schedule+. This allows a company to roll out Outlook in phases while enabling full communication between the old and new messaging systems.
Message Recall If a user sends a message that is inaccurate or inappropriate, they can attempt to recall the message from the recipients. Message Recall can either delete or replace the original message. Message Recall works across servers and across the Internet, but it will only recall the message if the recipient has not read or moved the message and if the recipient is also running Microsoft Outlook. If the recipients are not users of Microsoft Outlook, they will receive an e-mail message informing them that the sender would like to recall the earlier message.
NOTE: If you want to replace a message, you must send a new one. If you do not send the new message, the original message is still recalled.
Meeting Planner Outlook makes it easy to schedule group meetings and invite attendees by displaying the free and busy times. Outlook will even automatically pinpoint the next available time for all attendees. See Figure 1.3 for an example.
Importing and Exporting You can import and export messaging information from several products, including Schedule+, MS Mail, ACT, ECCO, Sidekick, and Timex Data Link watches. Some of these converters are on the ValuPack CD-ROM that comes with Office97 or on the Microsoft Web site (www.microsoft.com/outlook/ ).
You can export Outlook data into comma- or tab-delimited files as well as Outlook .PST files for moving large amounts of Outlook data.
CAUTION: Be careful not to confuse the Windows Messaging System (WMS) client that currently ships with Windows 95 and NT Workstation 4.0. This client, while having many of the features of the older "full" Exchange client that shipped with Exchange 4.0 and 5.0, cannot by default connect to an Exchange server. Neither can WMS easily be upgraded to add the Exchange Server Service. Generally, an installation of the full Exchange client or Outlook is required to enable access to an Exchange server.
The Microsoft Exchange Connector for Lotus cc:Mail enables administrators to seamlessly integrate Microsoft Exchange into cc:Mail environments. Once installed, Exchange Server and cc:Mail systems can exchange messages and synchronize directories. The cc:Mail Connector supports both DB6 and DB8 cc:Mail post offices. By introducing Exchange Server into a cc:Mail environment, cc:Mail users benefit from Exchange Server's strong connectivity to the Internet and other systems. Also, customers can take a phased approach to migration that will cause minimal disruption with an organization. New technology acquired from Linkage Software has further enhanced the cc:Mail connector in Exchange 5.5.
FIG. 1.3 Using the Meeting Planner in Outlook.
With the recent acquisition of Linkage Software, Microsoft has gained a world-class, proven toolset to easily facilitate connection of Exchange to a legacy HOST-based IBM PROFS OfficeVision (OV) or SNADS installation. Options include not only mail and attachment exchange, but also automated directory synchronization functions.
As with the cc:Mail and MS Mail connectors, migration from these older technologies offers dramatically reduced administrative and maintenance costs along with a significant increase in end-user productivity via the graphical Outlook client.
Also obtained with the Linkage purchase was powerful technology to connect Exchange to a Lotus Notes system for both mail and attachment exchange as well as automated directory synchronization. In an improvement over the previous versions of the Linkage product, Exchange 5.5 no longer requires an installation of Microsoft NT SQL Server to handle the directory synchronization functions. Instead, the newly enhanced databases of Exchange itself are utilized, thereby further reducing administrative overhead and increasing performance.
Person to Person Key Exchange, which extended the functionality of the Key Management Server, provided in Exchange 4.0. Now, users from different organizations can exchange keys and certificates, enabling them to send signed and encrypted messages over the Internet.
Numerous updates have been made to the Key Management Server (KMS) to allow for the bulk creation and distribution of user keys, making it easier to enable an entire location or corporation to use these security options. The integration of KMS setup into the Exchange Administrator program makes overall management of the KMS much easier as well. Key recovery options are added, making it possible for an Exchange administrator to recover and reissue a user's key if the password is forgotten or if the user leaves the company without disclosing her password. Through this same mechanism it is also possible to revoke a user's key.
To better control an Exchange administrator's ability to affect key security, options are available to implement so called "missile silo" passwords, in which two different administrative passwords are required to change or disable certain security features.
Keeping in line with proposed Internet security standards, support for X.509v3 (enhancing the current X.509 support in Exchange) and S/MIME certificates such as VeriSign are anticipated as the standards become firmly established.
Post office protocol version 3 (POP3) is an open Internet standard that Exchange 5.0 offered in compliance with RFC 1939 and 1734. The Internet Engineering Task Force (IETF) is close to completing the standardization of new RFCs (2060, 2192, 2193, 2195) for Internet Message Access Protocol 4 revision 1 (IMAP4rev1). Actually, IMAP4 has been around since 1986, when it was originally developed at Stanford University, but its abilities have been lost due to the public's focus on POP clients. The key features of IMAP4 over POP are as follows:
As a result of supporting both POP3 and IMAP4, any mail client that meets these standards can access and utilize Exchange as a mail server. Exchange handles inbound and outbound mail requests from these POP3 or IMAP4 clients and then grants them access to their mailboxes on the Exchange server or routes their submitted message to appropriate Exchange users or to the Internet as SMTP mail. As support for the IMAP4 standard spreads across the industry and the Internet, users everywhere will be able to have most of the features previously only found on proprietary, non-standard mail systems.
Furthering Exchange's flexibility, it's possible to switch seamlessly between any of the suite of clients (Outlook, POP3, IMAP4, and so on). All IMAP4 messages can be stored on the Exchange server, providing a single-message store. Additionally, all POP3/IMAP4 message accesses are protected via security from clear-text authentication to NT's Challenge/Response validation. Secure Sockets Layer (SSL) can be used in conjunction with clear-text authentication for encryption. See Figure 1.4 for the basic flow of POP3 or IMAP4.
FIG. 1.4 Basic Flow of POP3.
To support directory access for POP3, IMAP4 and Outlook Web Access clients along with other types of Internet-oriented applications, Exchange 5.5 enhances support for LDAP (Lightweight Directory Access Protocol) to meet the forthcoming version 3 standard. LDAP is an adapted subset of the X.500 standard that has been developed for the Internet to ease mail addressing issues between directory types that exist in various mail systems that touch the overall Internet. LDAPv3 is currently being defined by the IETF, with heavy involvement by Microsoft.
One key new feature of LDAPv3 enables mail systems to more easily participate in directory synchronization as solutions are developed to facilitate this need. A new LDAP API has been proposed to assist developers in making these directory connections. "Referrals" are also possible, allowing a corporation to link together several LDAPv3 based directory systems into one common lookup. Microsoft Exchange supports any client that implements the LDAP version 3 specification, including the latest versions of Netscape Communicator, Internet Explorer, Outlook Express, and other LDAP client providers.
The indexing associated with LDAP conventions enables users to actually search for a user in the directory based on limited criteria, such as first name and department (using wild card characters if desired), when perhaps the last name is not known. An Exchange administrator can selectively lock out certain directory attributes to non-authenticated, anonymous users (such as home addresses or other sensitive information). See Chapter 15, "Information Store Configuration," on securing directory attributes from non-authenticated, anonymous users. See Figure 1.5 for the basic operation of LDAP.
FIG. 1.5 LDAP Basic Operation.
Coupled with Internet Information Server, Active Server components give developers the building blocks to enrich web sites with Exchange functionality, such as messaging, threaded discussion, and directory services. For example, Microsoft completed an Active Server application called Outlook Web Access (OWA). Web Access gives a user the ability to retrieve e-mail, access his server-based calendar, set up "rules," and of course access Exchange server-based public folders by using a standard browser running on any of a wide range of platforms, including Macintosh, OS/2, or UNIX. Web View gives users more freedom to check e-mail wherever they are. With the advent of "Internet Cafés" and Internet kiosks, users can check their e-mail from anywhere in the world by simply logging onto their companies' Web sites. Please see Figure 1.6 for a basic flow of HTTP.
Exchange 5.5 also includes several tools to make creation of Exchange public folder based web applications easier. Electronic forms can be easily created in the Outlook Forms Designer then processed by a new wizard to convert the functions into HTML and Active Server elements. This wizard output can then be opened in Microsoft's Visual InterDev tool (the code with a single license is included with Exchange 5.5 server) for further customization and then integration with Exchange's public folders and IIS. Once properly set up, it is possible for any Internet browser to access these forms and folder-based applications for usage from any client platform. Many corporations will use Exchange public folders in this fashion to create a multifaceted intranet from which users can use the standard Outlook clients or a web browser to manipulate data and collaborate in workflow.
FIG. 1.6 Basic Flow of HTTP.
Microsoft is firmly committed to supporting all Internet standards, especially those related to security. The Simple Authentication and Security Layer (SASL), pending ratification by the IETF, is a supported option to force SSL authentication before SMTP messages will be accepted by the server. This feature is used to allow only secure SMTP-based connections between Exchange servers over the Internet, or to effectively restrict unauthorized access to the Exchange server via SMTP.
The Internet Mail Service's ability to connect one Exchange site to another across the Internet uses SASL and other encryption options to make the Internet a more acceptable messaging "backbone" for global corporations.
Microsoft has shattered the 16 GB limit that existed in Exchange 5.0 with new JET database technology that raises the limit to 16,000 GB (16 TeraBytes) in each of Exchange 5.5's databases (PRIV, PUB, and DIR). Combining this dramatic enhancement with the fully relational database structure and SQL-like transaction-logging functions of Exchange opens Exchange to nearly limitless possibilities for managing very complex messaging-based applications.
Another exciting and much-requested new feature of Exchange 5.5 is the ability to recover deleted messages and folders. Essentially, a "tombstone"/recycle bin concept has been applied to the message store so that when objects are deleted they are not removed from the database until a specified number of days have passed or a backup of the server is made.
Message flow is the path a mail message takes as it moves from one recipient to another. Exchange determines whether the message will route inside of a server or between servers by comparing the recipient's address with the addresses on the local site and those in the routing table (see definitions at the beginning of chapter). Messages will flow between servers if the address is in the routing table or within the same server if the address matches those in the local site. Before jumping into message flow, you must understand what Messaging Application Programming Interface (MAPI) is, first.
MAPI (Messaging Application Programming Interface) is a set of functions that can be called by C, C++, and Visual Basic programs through Windows Dynamic Link Libraries (DLLs). MAPI enables custom programs to can control and manipulate Exchange objects (see Figure 1.7). A powerful extension to Exchange, MAPI provides support for developers to enhance the core functionality built into Exchange.
FIG. 1.7 The MAPI framework provides the map for designing Exchange applications.
MAPI has the following five components:
When the client application is using a function library, messaging services are processed by sMAPI or CMC. The CMC interface is an API layer defined by the X.400 API Association. CMC is similar to sMAPI but is specially designed to support cross-platform development. When MAPI objects are being accessed and manipulated, client requests are serviced by OLE messaging or MAPI itself. The OLE messaging component enables development by using tools such as Visual C, Visual C++, and Visual Basic; MAPI itself is a powerful, object-oriented C++ interface that enables complex manipulation of folders, forms, and messages. The MAPI service providers then perform the requested actions for the client and pass back action through the MAPI subsystem to the MAPI client.
TIP: In addition to the tools and sample applications provided by Microsoft, many utilities for Exchange are available from third-party companies. These utilities, which are discussed in Chapter 31, "Using Advanced Outlook Features," consist of gateways, connectors, Visual Basic custom controls, and administrative utilities.
Many third-party developers (Lotus Development Corporation, for example) have switched from proprietary messaging standards, such as Vendor Independent Messaging (VIM), to MAPI for designing messaging applications. This trend reveals the strength of the MAPI standard of the multitude of development tools that will emerge for designing MAPI applications.
MAPI is the glue that enables client applications to converse with the server to build a robust communications architecture.
Here are the basic steps a message goes through when the receiver is on the same server as the sender. This process is detailed in Chapter 2, "Understanding Exchange's Organization Sites."
Here are the basic steps a message goes through when the receiver is on a separate server. This process also is detailed in Chapter 2, "Understanding Exchange's Organization Sites."
FIG. 1.8 Message flow within one Server.
FIG. 1.9 Message flow between servers.
Many critics attempt to compare Lotus Notes and Exchange, but no direct comparison can be made. Exchange has been designed from the ground up as an X.400/X.500-based enterprise messaging system. The MTA is designed to meet the exacting standards of 1984, 1988, and the proposed 1992 X.400 standards. The directory of Exchange is based on an extended version of X.500. Notes, on the other hand, began its life as a system of flat-file document databases that could replicate across multiple servers. Messaging was added as a way to enable additions to be mailed in to a database. Messaging has been enhanced in each version since Notes 4.0 to approach the needs of an enterprise messaging system. Currently, the internal mail engine of Notes 4.5 is still based on Lotus proprietary standards, but Lotus offers a series of free MTA add-ins to handle X.400 mail, SMTP mail, POP3 support with plans for LDAP and IMAP support later.
NOTE: Novell's GroupWise and Netscape's SuiteSpot are the two other contenders in the ring with Lotus Notes. Due to the relatively short time SuiteSpot has been on the market, comparative information is changing daily and should be retrieved from. Novell's GroupWise version 5 has been available for nearly a year, but since it is based on older Novell server technology it has simply failed to capture a significant portion of the market mindshare.
On the other hand, Notes and Exchange have been old foes and the core differences between the two products have been the same through recent versions. Thus, a section comparing Notes to Exchange follows. Comparative information on Notes is available at the same Microsoft web address.
A significant limitation of Notes is the lack of a "site" concept as used in Exchange. Exchange combines servers into logical entities called sites for easier administration. Moving a user's mailbox from one Exchange server to another within a site is a snap, requiring no involvement of the user and especially no alteration of the user's mail address. Adding a new server to a site is also very easy, with little customization required--just point the new server at an existing server for automated configuration and integration.
The Notes directory itself is loosely based on X.500 standards and has been since Notes version 3.0. Provisions are included for all of the components of an X.500 naming scheme and most of the fields associated with extended X.500 are included.
In terms of messaging, Exchange far exceeds the functionality of Notes version 3.x. Notes version 4.x has made significant strides in providing enhancements to messaging elements. Unlike MS Mail or cc:Mail, however, Notes has no legacy in shared file system mail. Notes has been essentially client/server from the beginning. Lotus recently has stated that Notes is the upgrade path from cc:Mail to a client/server messaging system. For many cc:Mail installations this is potentially not desirable; thus, in Exchange version 5.0, Microsoft included a cc:Mail Connector and the capability to perform directory synchronization with cc:Mail. As previously noted, this technology has been enhanced in Exchange 5.5.
The two products can compete as groupware solutions, but Exchange can provide an entire messaging infrastructure to connect with legacy systems and heterogeneous environments because Exchange bases all of its "workflow" on the messaging infrastructure. Replication of data in Notes can only process by way of a direct connection of two Notes servers using a unique replicator service. Exchange, on the other hand, uses the messaging connectors across whatever paths are possible to send small messages from one site or server to a remote system. These messages are then reassembled and the data added into the remote server's applications and databases. This reliance on the mail system to move the replication messages enables a single Exchange server to easily replicate data with indirectly connected servers anywhere in the organization. Furthermore, since the replicated data is processed as small mail messages, use of the available bandwidth on the links connecting two servers can also be carefully controlled--unlike in Notes.
Both Exchange and Notes offer a "simple" forms and database development environment for basic users, and both offer several options for enhanced development with powerful programming environments. In Notes 4.x, Lotus has added a programming environment called Lotus Script, which is 95-percent compatible with Microsoft's Visual Basic. Lotus offers this tool as a way for Visual Basic programmers quickly to become productive developing Notes applications.
Exchange takes this extensibility several steps further with complete integration of Exchange with the full family of Microsoft development languages and tools. With the continuing enhancement of Internet components and web publishing via Exchange, all of the available Internet-oriented languages and environments are available for use and the Outlook forms to HTML/ASP Wizard makes it all easier than before.
NOTE: Several third-party developers offer gateway solutions to give Exchange tight application connectivity with Notes. With proper implementation, Exchange and Notes applications can coexist effectively in your environment as a unified workflow system.
Probably the most limiting factor of Notes that will not be corrected in the foreseen future is the basic flat-file design of a Notes database. Notes databases are also limited to 4 GB in size. Exchange, now capable of scaling to 16 TB in size, is based on a relational database structure that lends itself to many traditional Relational Database Management System (RDBMS) programming concepts and features. Notes can attempt to address some of these limits with programming tricks and even replication to external SQL platforms, but the fundamental products that most clients will be working with do not take advantage of these workarounds.
Lotus Notes does have a perceived advantage over Exchange when it is used as groupware. From the market's perspective, the product is mature, and Lotus has made several enhancements in it over the years. Exchange 5.5 has been enhanced in the area of groupware development, with the addition of Exchange Server-based scripts to combat this advantage that Lotus had over it. The only actual advantage that Notes has over Exchange is in regard to "filtered replication." Notes offers administrators and developers (as well as end-users) numerous simple ways to filter data that will be replicated from one server database to another or from the server to a client. Look for Microsoft and their partners to overcome this limitation and to market Exchange very aggressively against Notes this year.
In addition to Notes's base functionality of providing groupware solutions inside any enterprise, many organizations have adopted an information distribution channel by providing Notes databases of information or direct feeds from their product support. Companies such as SAP currently use Notes as a means to support their product, but with the dramatic rise of the Internet, most companies are moving to a web-based support and information distribution-based model. Compaq and BAAN are examples of large corporations with mature installed Notes infrastructures that have recently dropped Notes and migrated to Exchange. Many more corporations are following suit and will continue to do so.
Interestingly, when MS Mail was in production, Microsoft internally did not use its own shared-file e-mail system. Instead they used its client interface on top of a proprietary UNIX-flavored system called Xenix mail.
To prove its commitment to the Exchange product, Microsoft has since moved all its internal mail systems to Exchange. At the time of this writing, Microsoft is on Exchange world-wide, with over 100 locations and close to 300 Exchange servers. The bulk of these servers are dedicated messaging servers, followed by nearly as many dedicated public folder servers. They have well over 15,000 public folders in use, with the majority of them used for development-tracking purposes (for build schedules, early adopter-tracking, and so on) but also used for such diverse functions as threaded discussions on almost every topic, and even online sales classifieds.
On the client side, Microsoft has moved to Outlook as the standard client browser to reinforce Microsoft's commitment to their own messaging platform.
Exchange has picked up considerable momentum since its first release in April 1996.
There have been over 1.25 million Exchange seats deployed to date and around 90 percent of customers use Exchange for Internet Mail connectivity. Fourty-five percent (more than one response could be marked) of those use Exchange for pieces of the company intranet. There are over 125 companies actively developing applications and over 15,000 professionals trained on the product.
Exchange migrations from MS Mail are a natural evolution and Microsoft spent a lot of marketing effort in 1996 to urge companies to make this move. Much of 1997's efforts have been focused on migrations from cc:Mail, Notes, flavors of UNIX POP/SMTP mail, and legacy HOST systems like PROFS. Software Spectrum has seen work in all of these areas with a particular focus on Notes to Exchange migrations.
With the richness of administration and development features in Exchange 5.5, even though only in its third release, expect Exchange to become a dominate force in the workflow/groupware arena to couple with its current dominance in messaging. These are exciting times for Exchange users and developers!
