I get asked many times why should one switch to Outlook 2007 from Outlook 2003 when using it with Exchange 2007 platform. I understand the reason as besides the obvious “it’s the latest and greatest” it’s not enough reason for an Enterprise environment to upgrade. Considering effort involved in upgrade, it could take long time to plan, test and upgrade all Outlook clients.

The information is published many times as to why Outlook 2007 is better choice and why the effort to upgrade is worth every penny. What I am going to do here is just an aggregation of the information available elsewhere to make it easier for the reader.

When used in conjunction with Exchange Server 2007, Outlook 2007 client provides numerous benefits and improvements over previous versions of Outlook clients including Outlook 2003. This document outlines the benefits of Outlook 2007.

Features and Benefits

Auto Discovery

Microsoft Exchange Server 2007 includes a new Microsoft Exchange service named the Autodiscover service. The Autodiscover service configures client computers that are running Microsoft Office Outlook 2007. The Autodiscover service provides access to Microsoft Exchange features for Outlook 2007 clients that are connected to your Microsoft Exchange messaging environment.

The Autodiscover service uses a user’s e-mail address and password to provide profile settings to Outlook 2007 clients and supported mobile devices. If the Outlook 2007 client is joined to the domain, the user’s domain account is used.

Another benefit of Autodiscover service with Outlook 2007 client is when disaster recovery is required in case of a server failure or a site failure, the downtime could be mere minutes where as with Outlook 2003 clients, profile reconfiguration is required which can delay client activation for new location of mailbox database or mailbox servers.

The Autodiscover service configures Outlook clients by automatically configuring the settings for the following items:

Mailbox server name

Offline Address Book download location when Outlook 2007 is used in Cached mode

Availability service URL

Out of Office (OOF) URL

Outlook Anywhere configuration details for remote clients

Authentication method

Unified Messaging server URL

Web-based Offline Address Book

Exchange Server 2007 introduces a new mechanism for distributing Offline Address Books (OAB) that doesn’t require Public Folders. It instead uses HTTP(S) and the Background Intelligent Transfer Service (BITS). There are several potential advantages of the new distribution mechanism including supporting more concurrent clients, reduced bandwidth usage, and more control over the distribution points. The new distribution mechanism requires Outlook 2007 and Outlook 2003 clients will still require Public Folder Distribution of OABs.

The benefits of web-based OAB download mechanism include:

– Throttled Downloads to preserve bandwidth

– OAB can be located on any domain joined server, reliance on Public Folder is removed

– Change in properties does not cause full download

– Downloads are small and differential in nature

Availability Service

The Exchange Server 2007 Availability service improves free/busy data access for information workers by providing secure, consistent, and up-to-date free/busy data to clients that are using Availability Web Service (like Microsoft Office Outlook 2007 or Exchange 2007 Outlook Web Access). Outlook 2007 uses the Autodiscover service to obtain the URL of the Availability service.

Unlike previous versions of Exchange, free/busy data does not have to be stored in public folders; thus it eliminates the issue with replication or latency experienced in previous versions. Instead the free/busy data is retrieved directly from the calendar of target mailbox via the Availability service.

Along with new Calendar Assistant functionality in Exchange 2007, the Availability service provides a methodology by which end users will be able to see free/busy data in real-time that is always up to date.

Calendar Assistant functionality only available in Outlook 2007 and later versions provides feature rich calendaring functionality and aids user in planning of a meeting. Suggested Times pane allows users to perform “what if” scenarios for the meeting. By selecting different days in date picker or changing meeting length using duration control, the suggested meeting times are automatically displayed in meeting suggestions list. This helps user make the meeting time most compatible for all attendees and avoid possible conflicts.

Resource Assistant

Exchange Server 2007 introduces changes to the resource booking architecture that address many of the problems and limitations found with pre-Exchange 2007 resource mailboxes. This new architecture is implemented via the new Resource Assistant.

The benefits of new Resource Assistant include:

– The Resource Assistant reads free/busy information directly from the Calendar of the resource mailbox, the resource can be booked without worrying about a “decline” message coming back due to conflict.

– Integrated Room Scheduling in Outlook 2007 allows users to quickly locate and select “Room” type resource mailboxes.

– Resource specific Schema attributes introduced in Exchange 2007 provides a mechanism to quickly distinguish between user and resource mailboxes and to search for resources based on user criteria

– A scheduling policy defines “who can book what when”. For example, for a specific user who should never receive an automatic “decline” message from a resource mailbox, a policy can be configured to forward the meeting request to a delegate.

Out of Office (OOF) Assistant

Exchange 2007 (including OWA) and Outlook 2007 provide several improvements to the Out-of-Office feature.

Using Outlook 2007, the new OOF architecture allows for much more granularity between internal OOF and external OOF messages. Users can specify text for just internal recipients, or internal + external recipients, with complete independence between the two OOF messages.

Users can now schedule when your OOF message is sent. One obvious benefit of this is that you can pre-create your OOF message(s) and set the desired schedule. When you leave the office, your messages are automatically sent, and upon your return, your OOF is automatically disabled. This is especially helpful when preparing for an extended period of absence, such as a business trip or vacation.

New functionality allows users to choose to send OOF messages to both internal and external recipients, with different OOF messages for each audience. Also, the new OOF architecture provides an option that allows you to send external OOF messages only to people within your Contacts folder.

Managed Folders

Exchange 2007 makes it possible for users to participate in the Messaging Records Management (MRM) process by exposing special mailbox folders called Managed Custom Folders. Managed Custom Folders look just like regular mailbox folders in users’ mailboxes except they cannot be moved, renamed or deleted (unless decommissioned by the administrator).

Administrators can create “managed custom folders,” folders with configurable names and brief policy descriptions that appear in Outlook and Outlook Web Access. These are mailbox folders (not public folders) that map to the various classifications of e-mail in your enterprise. Administrators can push these into the mailboxes of specific users. Self service model is also available, whereby a custom web application can leverage Exchange web services to allow users to choose their own folders from a web page. Each one of these folders can have its own policy to control the lifespan of the e-mail.

Partial Item Change Download

In earlier versions of Exchange with an Outlook 2003 cached mode client, changes to messages are tracked at the message level. Therefore, to reduce the number of bytes uploaded to the Exchange server, Outlook 2003 only uploads changes to specific message properties instead of the whole message. However, the download traffic from Exchange to the Outlook cached mode client is not optimized. If a property is changed on an existing message at the server then the entire message is re-synchronized down to the Outlook cached mode client.

This behavior changes with Exchange 2007 and an Outlook 2007 cached mode client. Every existing message is divided into a number of “sections” that are tracked independently. If some part of a section is modified, only that section is then re-downloaded to the Outlook client. This significantly reduces the number of bytes going from the server to the client.

Message Classification

Message classifications are a Microsoft Exchange Server 2007 and Microsoft Office Outlook 2007 feature that is intended to help organizations comply with their e-mail policies and regulatory responsibilities. When a message is “classified,” the message contains specific metadata that describes the intended use or audience of the message. Outlook 2007 may act on this metadata by displaying a user-friendly description of the classification to senders and receivers of a classified message. In Exchange 2007, the Microsoft Exchange Transport service may act on the metadata if there is a transport rule that meets specific criteria that are configured by the Exchange administrator.

Exchange 2007 ships with several default message classifications that can be applied to messages by enabled Outlook 2007 clients. For example, the Attorney/Client Privilege (A/C Privileged) message classification can be used to communicate the level of confidentiality that needs to be maintained by both Sender and Recipient. By default, a message classified as A/C Privileged simply displays information about the intended audience for the message. However, you can configure a transport rule that returns A/C Privileged messages if the message is addressed to a recipient that does not meet the conditions (e.g. group membership) of the rule.


Outlook 2007 introduces numerous productivity enhancements to help users manage information easily and collaborate more effectively.

Instant Search: Office Outlook 2007 provides a new fast way to find your information, no matter which folder it is in. Outlook now uses the same search technology that Microsoft Windows does, to deliver fast results regardless of mailbox size. In addition, an improved visual design displays each individual result of your search immediately, as soon as it is available, while the search is still running. Search now appears in the same place no matter where user is in Outlook.

Color Categories and Roaming: New Color Categories gives users a quick, visual way to customize items and to distinguish items from one another, making it easy to locate information. With Exchange Server 2007, categories are now available on all of the computers that users work on.

Attachment Previewing: Using the new Attachment Previewer, users can view attachments from within the Reading Pane by making only a single click. This improvement saves users time and allows users to view attachments in context with the e-mail message.

To-Do Bar: The new To-Do Bar integrates tasks, e-mail messages flagged for follow up, upcoming appointments, and calendar information in one convenient place. It also includes tasks from the Microsoft Office OneNote 2007 note-taking program, Microsoft Office Project 2007, and Windows SharePoint Services 3.0 Web sites. The To-Do Bar gives users a consolidated view of priorities for the day.

Task integration on the Calendar: Outlook 2007 integrates tasks on the calendar into the Daily Task List so that users see them displayed beneath daily appointments and meetings. To allot time for working on a task, users can simply drag the task onto a calendar. When users complete a task on a given day, the task sticks to that day, providing a visual record of the work that was performed. Tasks that you do not complete roll over to the next day, and accumulate until user marks them as complete.

Feature Comparison

The table below highlights features supported in Outlook 2007 which are not supported in Outlook 2003.

Feature Outlook 2007 Outlook 2003
Attachment preview Yes No
Color categories Yes No
Delay message delivery Yes No
E-mail postmarks Yes No
Internal/External OOF Yes No
OOF scheduling Yes No
Set/Use multiple signatures Yes No
Calendar overlay mode Yes No
Calendar publishing Yes No
Calendar snapshot Yes No
Calendar view has tasks by day Yes No
Forward latest meeting Yes No
Scheduling assistant Yes No
Task integration on calendar Yes No
Electronic business cards Yes No
Shared workspace integration Yes No
Sharepoint lists Yes No
Add new RSS feed Yes No
Auto-account setup Yes No
Flag mail as task Yes No
Fluent user interface Yes No
Import/Export feeds Yes No
InfoPath integration Yes No
RSS integration (reading) Yes No
Send to OneNote Yes No
SMS/MMS integration Yes No
To do bar Yes No
Highlighted search terms Yes No
Search as you type Yes No
Search filters Yes No