The Great Pretenders: MAPI Connectors To Trick Your Outlook

Ersatz Exchange Servers save companies licensing, training and maintenance costs. And Stalker's CGPro would fool anyone.

July 22, 2003

13 Min Read
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There are advantages and disadvantages to spoofing Outlook into using its native protocol to talk to a non-native back end. On the plus side, Outlook-to-Exchange communication via MAPI relies on RPCs (remote procedure calls) as a transport mechanism, increasing the number of packets that need to be exchanged between the client and the server. The increased packet overhead makes the bandwidth for dial-up connections a real bottleneck in the Exchange world. MAPI-connector technology avoids this overhead by converting MAPI to a less-bandwidth-intensive transport on the client before it traverses the network.

On the negative side, MAPI is Microsoft's protocol. It is documented (though not well), and Microsoft remains committed to using it, not only for Outlook but also for the e-mail hooks other Office applications use. Of course, that doesn't mean Microsoft won't pull the rug out from under MAPI or change it enough so that existing products no longer

function as intended. However, because MAPI is embedded in so many Microsoft and third-party applications, this scenario is unlikely, but forewarned is forearmed.

Just the Two of Them

We tested two contestants: Stalker Software's CommuniGate Pro (CGPro) mail server and SuSE Linux's Openexchange Server (SLOX). Because SLOX doesn't yet have a MAPI connector, it lacks several crucial capabilities. For this reason, we tested both products but did not rank the pair against each other. SLOX may be missing a MAPI connector, but it does have Outlook replication technology that works well.But why is SLOX lacking a MAPI connector? Here's our short tale of woe: SuSE assured us that its MAPI connector would be available in time for our tests. When we installed the product in April, the CD didn't have the connector, but we weren't worried. Toward the end of April, when it still wasn't available, we started to ask our SuSE contacts about it. Finally, after a series of e-mail and voicemail messages that some might term threatening, we got the company's final answer--no connector until late this year! We asked why and were told, "after all, this is open-source code and it's difficult to predict when something will be finished." We hope this doesn't become a common excuse in the open-source community.

And what about the other vendors in this supposedly exploding market? We contacted most of the first- and second-tier mail-server vendors, and even some third tier, to discuss our tests and their plans for moving into the Exchange Server replacement market. Many of these vendors said they are interested in entering the MAPI-connector market but most are still at the planning stage. In particular, keep your eyes on Rockliffe. You should see something from this vendor soon.

Oracle and IBM have MAPI connectors but declined to participate in our tests. Oracle purchased an Outlook connector when it bought Steltor in 2002 and rolled that technology into its Collaboration Suite. The folks at Oracle talked about wanting to compete against Microsoft and IBM-Lotus but, in our opinion, they didn't have a good reason for declining to participate in this review. IBM's Lotus division has a MAPI connector for Domino but the company is in the process of moving the development of this connector in-house. Initially IBM agreed to participate, but later it declined. Ironically, the third-party developer for IBM's old connector was Microsoft.

The SCO Group has a MAPI connector for its SCOoffice Mail Server. SCO suspended shipment of its Linux-based products in May because of its legal battle over Linux. The company contends Linux is an unauthorized derivative of Unix. SCOoffice Mail Server can run on UnixWare 7 with Linux Kernel Personality, but with all the legal maneuvering going on, SCO bypassed the chance to participate in our tests.

Exchange Rate



MAPI Features
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Our efforts to get IBM, SCO and Oracle to participate in our tests confirmed one thing: Plenty of Exchange Server replacement products exist, and more are on the way. That means there's money to be made and money to be saved. Software costs, training and platform choice are the key factors for any company considering implementing an Exchange Server replacement. Based on pricing from Microsoft's Web site, a 200- or 1,000-user Exchange 2000 server would cost about $70 per user, assuming you could support 1,000 users on a single Exchange Server and with no volume discount given. SLOX runs about $41 per client for a 260-user groupware server and $33 per client for 1,010 users. CommuniGate Pro's licensing is different, but the savings are even better. A CommuniGate Pro license for 200 groupware clients runs $40 per client, and the license for 1,000 users drops the price per client to $22.

We know the initial purchase price of a product is a small part of the TCO story, but based on our experience with Exchange, CGPro and SLOX, the ongoing management and administration costs for the non-Exchange products would at worst be equal to Exchange. Realistically, we're sure those costs would be less. On the training front, because many corporate users are using Outlook or Outlook Express, retraining them to use Outlook with a third-party Outlook connector is a nonissue. However, it's a huge factor in any integration strategy. And finally, the third-party products provide platform choice. CGPro runs on 28 platforms--including Windows 2003 server--and doesn't force your organization to upgrade to Active Directory to implement the latest release. SLOX runs on SuSE Linux only, so you don't have a choice there unless it's a choice between Exchange on Windows or an Exchange-like product on Linux.

For now, if you're seeking a server with Exchange Server functionality for your Outlook clients you still have a choice. Use Exchange or use Stalker's CGPro. If you need browser-based access to groupware functionality, put SLOX on your list. By year's end, you should have additional Exchange Server replacement products to consider.We tested version 4.0.6 of CommuniGate Pro running on both Windows 2000 server and on Solaris 8 on a SPARC platform. We wanted to see if there were any differences in the basic functionality of the mail server and MAPI connector on different platforms. Happily, we didn't find any. CGPro has two primary management interfaces--a browser interface and a CLI (command-line interface) accessed with telnet. The CLI also serves as CGPro's API. Stalker provides libraries for PERL and Java for access to the CLI API. Unless you look at the general settings page on the Web interface, you won't know which platform is hosting the server software. We also examined the next version of CGPro, version 4.1, which was in beta (see "Beta Adds Calendar, Contacts,"). Version 4.1 brings CGPro more in line with the browser-based groupware features included in SLOX.

We tested Stalker's MAPI connector, version 1.0.60, with Outlook 2000 and Outlook 2002 using Windows 98, Windows 2000 and Windows XP as client operating systems. Neither the version of Outlook nor the underlying OS made any difference in the MAPI connector's functionality. Stalker's MAPI connector has been in development since early last year and has been available since the first shipment of version 4 in October of 2002. After more than a year and a half of development, the product has greatly matured. For instance, offline functionality has improved dramatically. In fact it's safe to say Outlook behaves as expected in off-line mode with the latest version. We viewed messages, deleted messages, moved messages from one folder to another, and wrote and queued-up new messages and replies for delivery when back online. There were zero glitches.

CGPro is a standards-based mail server that supports POP, IMAP and Web clients out of the box. Stalker's intelligent approach to groupware design translates into cleverly incorporating calendar and contact standards as well. The MAPI connector sits as a shim between Outlook's MAPI interface and CGPro's "extended" IMAP interface. The connector translates MAPI requests into IMAP requests at the server and converts data objects into vCard and vCalendar data for storage and retrieval. With the latest release of the MAPI connector, Stalker has provided a slate of command-line options for the client installation that makes it possible to script the installation of the connector for your clients.



CommuniGate Pro
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Stalker has engineered the connector in two parts. The Loader, which runs on the client, launches when Outlook starts and makes the initial connection to the CGPro server. The server then automatically sends the main part of the connector code to the client if the client code isn't up-to-date. This architecture lets administrators place updated code on the server that is implemented automatically on the client the next time the client fires up Outlook. Reinstallations of the client connector are necessary only if Stalker updates the Loader. We tested the MAPI connector over dial-up, broadband and LAN connections to make sure this didn't cause a problem with slow connections. The 56-Kbps dial-up connection was noticeably slower when loading but very responsive otherwise, and we had no trouble with the higher-speed connections.



CommuniGate Pro
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Once everything is up and running you can do nearly everything in Outlook you could do if you were using an Exchange Server on the back end. We shared mail, contact and calendar folders with other users and connected to their shared content. We created group meetings using real-time free/busy searches that sent mail notification to requested attendees. When we received meeting requests from co-workers, we could accept or decline the meeting with the push of a button that automatically sent our reply to the originator via mail and put accepted meetings on our calendar. The connector supports ACLs (access-control lists) that let you give some users limited access while giving others full access to your folders. What's missing? Stalker's CGPro MAPI connector cannot sort contacts by category.

CommuniGate Pro, starts at $1,698 for 25 MAPI connections, Stalker Software, (415) 383-7164, (800) 262-4722. www.stalker.comSLOX is an integrated set of open-source products comprising Postfix, Cyrus IMAP, Apache, OpenLDAP, SpamAssassin and Linux kernel 2.4.19. The folks at SuSE have wrapped these separate products into a cohesive whole that includes a unified, browser-based administrative interface. In addition to offering standards-based e-mail via POP, IMAP and the Web, SLOX boasts a number of Web-accessible groupware features, including group scheduling, discussion forums, and task and project management. It also has a rudimentary document-management and knowledge-management system.



SuSE Linux Openexchange Server
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Because your Outlook users aren't using MAPI, they will not have the kind of functionality they'd have if they were using an Exchange server. SLOX's Outlook replication works in batch mode rather than in real-time. Real-time communication between Outlook and the Exchange replacement server is the key to up-to-the minute server-based storage of your data as well as such online activities as free/busy schedule checking when arranging a group meeting. Using replication technology, when you create a meeting in Outlook, it won't be reflected in your server store until your data replicates in batch mode and visa versa when using SLOX's browser access. Replication can be set to run on a schedule automatically or you can run a replication session manually. We tested both methods, and SuSE's replicator works fine. SLOX users also won't be able to access shared folders via the standard Outlook mechanisms. SuSE's Outlook connector promises all the missing functionality, but we'll have to wait until the end of the year to see if the company delivers on that promise.

SuSE Linux Openexchange Server (SLOX), starting at $1,249, SuSE Linux. www.suse.comRon Anderson is Network Computing's lab director. Before joining the staff, he managed IT in various capacities at Syracuse University and for the Veteran's Administration. Write to him at [email protected].

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Exchange Server Replacements

What looks like Microsoft's Exchange Server, responds like Exchange Server, offers full-featured mail, calendaring, group scheduling and task management like Exchange Server, but isn't Exchange Server? We tested third-party Microsoft Exchange Server replacements that offer Outlook users mail, calendaring, group scheduling, task management and notes for a fraction of the price of Exchange.

Based on our conversations with a number of mail-server vendors, we think you'll see the Exchange Server replacement market take off over the next year, but for now the pickings are slim. SuSE promised an Outlook connector for its Openexchange Server (SLOX) but failed to deliver. Oracle, IBM-Lotus and The SCO Group describe products that sound like what we're looking for, but they chose not to participate in our tests, so we can't tell if they're blowing smoke.

One of the products we tested fills the bill: CommuniGate Pro from Stalker Software. CGPro fools Outlook into thinking it's talking with Exchange running on Windows, when it's really talking to an imposter running on one of the 28 platforms supported by Stalker. CGPro supports POP, IMAP and Web clients out of the box, and it costs as little as $22 per client. While we were testing the shipping versions of Stalker's CGPro and SuSe's Openexchange Server, Stalker was at work on CGPro 4.1. We tested beta version 4.1b8 in our Real-World Labs® at Syracuse University as well as a beta "webskin," called EudoraLook, from one of CGPro's third-party developers, David Bakkers from Group Colleges in Sydney, Australia. The big news for this release is browser-based access to groupware features previously available only through the MAPI connector.Release 4.1 extends the functionality of calendaring, contacts, tasks, notes and group scheduling to CGPro users who want to access these features using a browser rather than using Outlook. In addition, Outlook users who occasionally use a browser to access their CGPro server have access to the same contacts for addressing mail on the Web as they do in Outlook. They also can add appointments and set up group meetings from a browser session. Because all the data is stored on the server when the user goes back to Outlook, everything he or she did during the browser session is reflected in Outlook.

The standard CGPro Web interface is a little rough around the edges--usable but utilitarian. Out of curiosity we tested EudoraLook 3.0b2 as an optional skin for the Web interface, and found it usable and visually pleasing, if a bit busy. To test this beta version of CGPro, we loaded our accounts with a year's worth of contact and calendar items by dragging them from production Outlook clients' local calendar and contact folders and dropping them in their respective server-based folders using the MAPI connector.

Once the data was available we checked the transfer for accuracy using the EudoraLook interface and found everything copasetic. Instead of a single "Create New" button for new messages, CGPro 4.1 lets you devise and edit new events, tasks and notes. We created personal recurring events, scheduled group meetings and accepted requests for group meetings, all from the safety and comfort of a Web browser.

CGPro lets you import and export vCard and vCalendar data through the Web interface. We examined the server files that contained the calendar and contact information and were pleased to see that the data is stored in standard formats: vCard for contact information and vCalendar for calendar information. We used Outlook's import utility to load exports from CGPro's calendar and contact folders without a hitch.

What's missing? Stalker has yet to implement a good method to create and schedule conference rooms, video projectors and other resources. The company includes a new rule action in 4.1b8--called Accept Request--that seems intended to facilitate automatic resource scheduling, but Stalker needs to expand on this feature. Also, though CGPro lets you share a calendar with a co-worker, it doesn't support delegation properly: An event can be added to the calendar, but the user's free/busy information won't be updated. Business applications white papers & research reportsBusiness applications books

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