Volume Number: 26
Issue Number: 01
Column Tag: New Tools for Collaboration

New Tools for Collaboration: A Passion for Exchange Clients

"Bells and whistles," or, "Do what you do well."

by William Smith

Microsoft Exchange Server offers basic collaboration tools such as mail, calendaring and a centralized address book, but also offers extended features such as tracking tasks, mobile syncing and telecom integration. In the corporate world, Exchange is the gold standard for messaging servers.

A server is not a server, though, without a client—a front-end "window" for the end-user. In a nutshell a client's responsibility is to take input from its user, send it to the server, receive information back from the server and present the results to the user. Exchange Server is built to communicate with a variety of clients. Some clients take advantage of a lot of Exchange's features while others trade complexity for simplicity.

Client preference is a passion for some users. For rational and irrational reasons of their own, they will defend their choice of client over any other. Their client may simply do what others don't, which is a rational choice, or their client may be made by "the blessed company" whereas the only other client with the same features is made by "the evil corporation", which is an irrational choice.

Simply put, Outlook for Windows is the gold standard of Exchange clients.

Huh? Is that a rational or irrational statement?

Outlook for Windows isn't a perfect application, but it is the only application that is 100% compatible with Exchange Server and of all of its features. It's the only client that can set server-side rules or tally surveys using voting buttons. It's the only client that can directly book meeting rooms or respond to meeting invitations with a proposal for a new time. It's the only client that can do everything that any other Exchange client can do and then still do more.

Outlook for Windows is the most complete Exchange client available. Logically, one Exchange client has to exist to be able to take advantage of everything Exchange can do. Why would anyone ever develop a server with features that no client uses?

While not nearly as feature-rich as Outlook for Windows, the closest equivalent in the Mac world will be Microsoft Entourage. For better or worse, it is the dominant Exchange client with the most history and greatest install base.

All other Exchange Server clients will fall into either the Desktop category or the mobile category.

Today's Mac Desktop has two major Exchange clients that are native to Mac (i.e. not Outlook for Windows running under a virtual machine like Parallels or VMWare). Until recently, Microsoft Entourage had been the only true Exchange client able to take advantage of the "electronic trinity" of mail, calendaring and contacts. Apple released Mac OS X 10.6 (Snow Leopard) in late August with Mail 4.0 making it the second player in the Desktop Exchange client market.

Figure 1. The electronic trinity

Microsoft Entourage X 10.1.4 offered a very limited Exchange experience when it was released in August 2003. It was a combination of IMAP for mail and WebDAV for calendaring and contacts. Entourage 2004 and 2008 introduced major Exchange feature improvements with support for public folders, delegation, Kerberos authentication and quota support to name just a few of the more advanced features. In mid August of 2009, Microsoft released a new major version of Entourage called Web Services Edition (13.0.0). While it looks like Entourage 2008 (12.0.0), the protocol for communicating with Exchange was completely replaced with a new one called Exchange Web Services (EWS), opening new doors for feature improvements.

Apple's release of Mail 4.0 along with updated versions of iCal and Address Book made Snow Leopard the second Exchange client for Mac to offer the "electronic trinity." Earlier versions of Mac OS X offered similar Exchange support to that of Entourage X, using IMAP for mail, WebDAV for calendaring and LDAP for contacts. However, Snow Leopard's applications now support the EWS protocol too, putting it on an even playing field with Entourage. Technically, by communicating with Exchange using the same language, neither application has an advantage over the other. Both can support the same Exchange features.

To date, no other Desktop client for Mac supports the "electronic trinity" with Exchange, but on the horizon stands Mozilla (http://www.mozilla.org/). Its Thunderbird mail client can access Exchange mail and it has built in LDAP support to search company directories for contacts. Its stand-alone Sunbird and Thunderbird-integrated Lightning calendar clients only support iCalendar, CalDAV and WCAP for network calendaring, however, support for Exchange Server is planned after Lightning 1.0 is released according to an interview with Louis Suarez-Potts and Stephan Schaefer, two developers on the Lightning project:

http://www.openoffice.org/editorial/mozilla_lightning_and_OOo.html. The interview is nearly four years old and Lightning 1.0 just went into beta on December 20, 2009. EWS, an openly documented protocol, is Microsoft's direction for all Exchange Server communications for Desktop clients, so the next logical step would be for Mozilla to integrate EWS into Thunderbird and Lightning.

Unlike the Desktop, a multitude of mobile clients like smart phones and PDAs can access Exchange. Other than manufacturer design, these devices differ in just one way. They use either the ActiveSync protocol, licensed by Microsoft, or the Blackberry protocol, licensed by Research In Motion (RIM).

ActiveSync is owned and licensed by Microsoft and is integrated into Exchange. It works using a "push" service, which is really more like a "pull/push" service. When ActiveSync is running on a smart phone, it is connected to Exchange via a long HTTP session. It makes the connection to Exchange using HTTP and says, "Don't respond to me unless you have a new message or 15 minutes have passed, whichever comes first." If 15 minutes have elapsed without a new message then the server responds with a message indicating it has no mail. The smart phone then starts a new long HTTP session.

Blackberry is a proprietary protocol owned and licensed by RIM. Although a Blackberry device can sync via a cable-connection to the Desktop computer, a more efficient method is to use a Blackberry Enterprise Server (BES) to act as an intermediary between Exchange and the Blackberry handheld device. Blackberry uses a true push instead of a pull/push to communicate with smart phones and handhelds. When Exchange receives a message, BES packages the data and sends the message to the phone using a very quick and bandwidth friendly communication.

If Microsoft offers EWS for Desktop clients and ActiveSync for mobile clients, then all Exchange clients can support all Exchange features. Correct?

Technically, yes!

That is: All EWS clients can support the same features and all ActiveSync clients can support the same features.

The purpose of EWS is to unify communications with Exchange Desktop clients so that all of them communicate with the Exchange Server the same way. The Macintosh Business Unit (MacBU) at Microsoft worked with the Exchange Server team to develop this protocol for not just Entourage for Mac but all future Exchange clients, including Outlook for Windows. With the release of Exchange Server 2010, EWS completely replaces the WebDAV protocol used by Entourage 2008 and earlier as well as earlier versions of Mac OS X. WebDAV is no longer available. That means only certain Apple Mail/iCal/Address Book clients and only certain Microsoft Entourage clients can communicate with specific versions of Exchange Server. [See Table 1.]

Table 1. Exchange server and client compatibility table

IMAP for mail and LDAP for directory services may still be available for all versions of clients working with all versions of Exchange Server, but Exchange calendaring has no substitute for WebDAV or EWS on the Mac.

Just like mobile phones aren't meant to replace Desktop computers, ActiveSync and Blackberry will most likely always remain "lite" Exchange clients since their focus is on mobility. Blackberry offers a handful more advanced mobile features, but ActiveSync is generally on par with RIM's product in terms of syncing and functionality.

If all Exchange protocols are "standardized" then won't all Exchange clients for Mac eventually become the same?

Just like Mac OS X is not the same as Windows, Apple's Mail/iCal/Address Book and Microsoft Entourage will never be the same. They serve two different audiences with some overlap in between. Apple's audience is consumer-focused whereas Microsoft is now leaning more heavily toward the enterprise market as stated in their blog: http://www.officeformac.com/blog/Ready-for-Snow-Leopard. Not only is Microsoft replacing Entourage with Outlook in the next version of Office for Mac, but they are also building in support for SharePoint and Information Rights Management.

Only Apple knows why it built native Exchange Server support into Snow Leopard. It's first attempt at a true Exchange client in Snow Leopard was clearly to offer basic Exchange features and to offer them well. Apple is well known for its simple presentation and elegant minimalism.

Microsoft, on the other hand, has been heavily chastised for Entourage's lack of parity with its Outlook cousin on Windows. After all, Outlook for Windows is the Exchange client gold standard and the same company makes both products. Because of the difference in protocols, Entourage has struggled to offer the same feature set as Outlook. (Outlook uses the MAPI protocol instead of WebDAV.) With the introduction of EWS, MacBU loudly touted the introduction of some features that had only been available in Outlook such as syncing categories, Tasks and Notes along with syncing message statuses—those little Forward, Redirect and Reply arrows next to messages.

Interestingly, while Apple, too, implemented syncing for Tasks, Notes and message statuses in its first EWS client, it didn't include categories. Is this an oversight, a yet-to-be-implemented feature or a conscious decision by Apple not to include them at all? Categories or Finder-style Labels don't exist in Mail to date.

Similarly, Apple has kept its Exchange client on the iPhone simple. ActiveSync does support Tasks and Notes but since its introduction in the iPhone 2.0 upgrade in July 2008, these features remain conspicuously absent whereas they were in high demand for Entourage users because of their availability in Outlook for Windows.

To compare Apple's Snow Leopard Exchange client with Microsoft Entourage and try to judge one better than the other is a battle best left for the faithful to fight. Those who try to draw such as conclusions have probably already made their decision before starting. True epiphany comes to those who examine their needs and choose the products better suited for them.

Very little in the decision to use Apple's Mail/iCal/Address Book versus Microsoft Entourage will actually be based on Exchange support. Again, since both are capable of using the EWS protocol, both have the potential to do what the other can do. The differences will be in the user interface and in finding a greatly needed Exchange feature that one offers but the other doesn't.

Mail, calendars and contacts sync well with both Snow Leopard's applications and Entourage and both return virtually identical information. The display of that information is one of the greatest differences between these two Desktop applications. Following are a few of the more noticeable differences.

Apple uses three different applications whereas Microsoft uses just one. Some users prefer Entourage because they like to see everything in one window even though they can still only view one function at a time without opening more windows. They prefer the interaction with one application compared to three. Other users don't mind Apple's three separate applications.

Only Entourage offers an additional view in three columns similar to its Outlook cousin. This view is optimized for today's widescreen laptops where screen real estate is at a premium. Only Mail, on the other hand, offers highlighted message threading, which makes viewing a multi-message and multi-user conversation much easier. Entourage offers grouping, which is nearly as easy to follow.

iCal's display of over-laid calendars is ideal for viewing multiple calendars at once, especially delegated calendars or calendars that are subscribed via a different protocol such as CalDAV for a Google calendar. Entourage only offers the ability to view one calendar at a time without opening more windows on the screen. Unlike iCal, it does offer a Work Week view in addition to a List view.

Figure 2. iCal's multi-calendar view

The address books in both Entourage and Snow Leopard offer the same content, but only Entourage allows the user to sort multiple contacts by a few dozen columns or designate E-mail addresses as "Work", "Home", etc. Both do a good job of normalizing formats for telephone numbers and both sync additional data such as iPhone photos from the Exchange Server when connected via EWS.

Categories in Entourage can by set on all items—mail, calendars and contacts—but only Apple's iCal comes close to categorization with its multiple calendar view. Nothing native in Mail or Address book allows the user to categorize, tag or color-code items for easier viewing and sorting. Furthermore, categories in Entourage sync with Exchange and with Outlook for Windows for those who work cross-platform at the office.

Figure 3. Entourage categories

Microsoft Entourage is a more complete Exchange client than Apple's Mail/iCal/Address Book simply because it offers more Exchange features. Similar to users comparing Entourage to Outlook for Windows, Snow Leopard will be compared to Entourage and later Outlook for Mac for some time to come. Users will compare the iPhone to Windows Mobile and Blackberry until it reaches feature parity.

Both Desktop applications sync Tasks and Notes with Exchange, however, as mentioned earlier, Apple's iPhone has yet to implement these features. Windows Mobile devices, which use the same ActiveSync protocol as the iPhone, and Blackberry devices both offer this support.

Surprisingly, both Entourage and Snow Leopard offer one Exchange feature that Outlook for Windows currently does not—multiple Exchange accounts. This discrepancy will be short-lived, though, when the next version of Outlook for Windows is released in Office 2010.

Both Entourage and Snow Leopard offer multiple calendars within one Exchange account as well as multiple address books. These are most often used to keep personal information and work information separate or to separate temporary data (e.g. travel schedules and hotel contacts) from permanent data. Entourage has a slight display issue where it places new calendar or contact folders created from other clients below existing calendars and contacts rather than under the account headings themselves.

Delegation support is mostly lacking in Snow Leopard whereas Shared Folder support is completely missing. This is an area where Entourage is better suited for collaboration in the enterprise while Snow Leopard is currently tailored to the individual user. While an iCal user can connect to another user's calendar as a delegate (someone permitted to act on behalf of the delegated account), neither Apple's Mail nor Address Book can connect as a delegate to another Exchange account. Calendars in both applications do offer a "Private" option to hide sensitive events from those who are connected across the network as a delegate. Only Entourage offers the ability to share folders and connect to shared folders, however, compared to Outlook for Windows, its sharing capabilities are limited to just the Inbox, primary Calendar and primary Contacts list.

Entourage can set a basic Out of Office message rule for Exchange 2003 accounts and a more advanced rule for Exchange 2007 accounts. Compared to Outlook, this is the only server-side rule it can set. Apple's Snow Leopard applications do not have this capability and its users must rely on Outlook Web Access (OWA) or set the rule using a different application or computer.

Figure 4. Out of Office Assistant in Entourage

Only Entourage supports public folders, a feature de-emphasized in Exchange Server 2007 and one that will probably be removed in a future version of Exchange in favor of Microsoft SharePoint. Apple probably made a conscious decision not to include public folder support in Snow Leopard to spend its development time elsewhere. While this is not a major drawback for new Exchange installations, companies with huge legacy public folder structures may need to hold on to Entourage a while longer.

For the most part, Snow Leopard and Entourage are on par with security concerns as is Apple's iPhone. All offer SSL connectivity support for encrypting traffic and both Entourage and Snow Leopard includes Smart Card support.

Entourage does, however, offer some additional security features for the corporate environment: Kerberos authentication for single sign-on and Client Certificate-based Authentication (CCA).

Kerberos authentication enables users to log in one time to a Mac that's connected to a directory system, such as Active Directory, and generate a ticket. That ticket can then be passed on to other servers transparently to grant the user access to those other network resources. The end result with Entourage is that the user never has to enter his credentials when connecting to Exchange, even if his account password has recently changed. Apple's Mail/iCal and Address Book applications do offer Kerberos support, but just not with Exchange.

CCA works with a certificate infrastructure. In a simplistic setting, a user can use a web browser to navigate to a secure internal website to request and download a certificate, usually a .cer file. Double-clicking this .cer file will install it into the user's keychain using the Keychain Access utility. The user's keychain is where other certificates and passwords are securely stored. Once the certificate is installed then the user can direct his Exchange account in Entourage to use the certificate in lieu of entering his name, password and domain information.

While Apple's iPhone has simplistic mail, calendar and contact applications, it offers two common Exchange security features that make it very secure for most uses. First, as of the iPhone 3.1 update, it enforces hardware encryption if the appropriate Exchange policy has been enabled. This applies only to 3G phones. The original iPhone does not support encryption and the 3GS is already encrypted.

Second, the iPhone supports remote wipe via OWA. If a user loses his iPhone and he's concerned that someone may hack into it and view sensitive data, then he can initiate a remote wipe without the aid of an administrator. A remote wipe takes about an hour for every eight gigabytes of disk and then the phone is restored to factory defaults. The best security for any mobile device is maintaining physical control. Stored data is inherently secure unless someone gains physical access. At that point, breaking the encryption can be relatively easy for someone knowledgeable.

Figure 5. Remote wipe via Outlook Web Access

One last note about mobile devices: Windows Mobile and Blackberry devices are capable of using digital certificates for exchanging signed and encrypted messages. The iPhone, on the other hand, does not support digital signing nor does it support user-installed certificates. If an iPhone user receives a message that has been digitally signed, he will receive no indication when a certificate is invalid or revoked. If he receives a message that has been encrypted, he will still be able to read the Subject but in place of the Body will see "This message has no content." It will appear to have "smime.p7m" as an attachment that is unreadable.

Not all users are created equal and, likewise, not every user will prefer the same client for use with Exchange. Understanding the pros and cons of different Exchange clients will help an administrator better determine which clients he can support and which clients he should support. Following are some ideas for when each client has its place.

Executives are most likely to be mobile users but will often have administrative assistants coordinating much of their calendar and contacts. While the iPhone may seem attractive at first, they often prefer to use a Blackberry or Windows Mobile device because of their more robust Exchange offerings. A physical QWERTY keyboard is often a "must have."

Administrative assistants are unlikely to be mobile and will need to coordinate meetings and messages for one or more executives. They deal with sensitive information, often about personnel or business transactions and need to keep a view on many things at once. A full Desktop Exchange client such as Entourage or, more likely, Outlook for Windows is essential.

The sales force is also more mobile but its focus is on customer relationships and phone time is often more valuable than text or E-mail time. The iPhone's user-friendly interface makes managing contacts not only easy to do but pleasant. And what salesman doesn't like to show off his gadgets?

Customer Service is sedentary and often behind a desk. Their needs are derived from customer contact as well and they are notorious for holding onto every client message as "proof" of something that may or may not ever happen. Entourage would be an ideal Mac client for them because of its categories and sorting capabilities. Messages can be automatically tagged with client contact information using Entourage's built-in preference for associating contacts with messages as they come into the Inbox.

Marketing and graphics professionals are often Mac diehards. Their E-mail, calendar and contact needs are straightforward and they often deal with the same clients and vendors over time. They build relationships less often but maintain those relationships in the long run. Apple's Mail/iCal/Address Book suite is fine for them. They may even prefer them to having an evil Microsoft product installed. If they don't have a need for Microsoft Office then the built-in clients may be just fine for them.

Exchange clients come with varying levels of support for Exchange features. Some offer complete support while others offer more basic support. That's not to say those with less support are lesser Exchange clients but rather they are made to target a certain user market. Users of Outlook for Windows, the gold standard of Exchange clients, probably never take advantage of more than 10 percent of its total Exchange feature set. Mac developers, especially Apple, recognize that fewer features executed well can be as productive for some users as trying to include every feature.

Users themselves know that their preference for a particular client isn't decided by quantity of Exchange features but rather quality and they're zealots for what works best for them. Their passion for a particular product isn't completely decided by rational analysis of features nor loyalty to a particular developer. Passion for a product really does stem from a mixture of both.

William Smith is a technical analyst supporting Macs in a Windows world in the Twin Cities, a six-year Microsoft MVP and is co-founder of the Entourage Help Blog http://blog.entourage.mvps.org. He can be reached at bill@talkingmoose.net.