Battle of the Ajax Mail Packages

Scalix and Zimbra offer promising e-mail solutions that exploit Ajax to offer rich Web clients.
Configuring the Products

Both Scalix and Zimbra offer command-line and Web-based configuration tools. And in both cases, you can do much more from the command line than you can from the Web. The philosophy seems to be that the Web should be used for ordinary day-to-day operations, such as adding a new user, and the command line is for more complex or less frequently used ones.

One headache both products share is that they have a ton of these command-line programs. Zimbra has 74 programs you can use to control its operation, and Scalix has 341 (yep 341) programs in its bin directory, and they are so closely named that you may go mad trying to remember the differences. For example, try figuring out whether you should be using omdelapppdl or omdelapppdln. As I said, a close reading of the manual is in order before you try anything fancy.

Zimbra comes configured with SpamAssassin and ClamAV already installed. Scalix supports any Milter-based spam and antivirus tools. It wasn't that difficult (with a little help from the very responsive support board when I made a stupid mistake) to install them.

You've Got Mail

There's no question that the Zimbra Web-mail interface is both more featureful and colorful. For example, put your mouse over a date and you see the calendar for that date. Mouse over an e-mail address, and you see the contact information for that person. Mouse over a Web address, and you see a thumbnail of the site. Unfortunately, it's still a bit glitchy, especially under Firefox. This is not a good thing for a product that wears an open-source pedigree so proudly. Hopefully, these issues will be resolved before the final release.

What Zimbra is currently lacking, however, is any kind of direct Outlook support. Even though the Web site claims Zimbra will interface directly with Outlook, this is in fact a TBA feature. So at least for the time being, Zimbra is available only via its Web interface or by IMAP/POP3.

Figure 2. Zimbra offers mind-boggling feature-rich Web mail.

By comparison, Scalix is almost pedestrian in appearance on the Web. If you don't look carefully, you could swear that you're using Outlook. That is probably by design, as Scalix wants to replace Exchange seamlessly. You can do pretty much everything via the Web interface that you can do directly from Outlook, except for anything having to do with mail filtering.

It's when you add the Scalix plugin to Outlook that Scalix really shines, however. I use Exchange on a daily basis at my workplace, and I am now using Scalix for my personal e-mail outside of work. Honestly, there's no practical difference between the two if you use Outlook. The mail-filtering options are a little different, but you really have to look hard to see where the two diverge. Among the more useful features that it shares in common with Exchange is the ability to define filtering rules that run directly on the server. And, because ActiveSync talks to Outlook, you can sync your PDA to your calendar, mail and contacts.

Figure 3. Scalix: any resemblance to Microsoft Outlook is purely coincidental.

Which to Choose?

If you're trying to pick one over the other, I'd have to recommend that you start by trying each of them out, because they both have free community editions. Zimbra is probably more of a one-click setup than Scalix, and it definitely involves less in-depth knowledge of things like LDAP. It also has a sweet Web interface that should only get better as it is further developed. On the other hand, it is still in beta as of this writing, and lacks Outlook connectivity.

Scalix shows all the signs of an Enterprise-facing solution. It's less intended for casual users setting up a personal server than for a departmental or corporate environment with many users and complex requirements. That being said, it wasn't that much of a strain to get it set up for my personal domains. But for me, the killer feature is the Outlook connectivity (and especially the free 25 licenses). Until clients such as Evolution become better integrated with PDAs and other groupware technologies, many of us are going to be stuck with Outlook as a mail client, and only Scalix is offering a free solution that everything can talk to.



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MadiKL's picture

Can I migrate from AtMail to Zimbra mail server?

Zimbra / Atmail

Links forever's picture

Zibra and Atmail is beautifull and extra functionally emial clients but now i'm used Zibra because it's faster than Atmail.

Ajax in email clients is good idea.

Scalix in Los Angeles

Anonymous's picture

Scalix will be exhibiting at the 2006 Southern California Linux Expo on Feb 11-12, 2006.

What about true interoperability for Linux Clients

Alan's picture

Good review, it matched my findings when I evaluated the products, but infinitely better worded than I could ever put it.

The thing that I find is still missing is true interoperability with Linux PIM clients such as Kontact and Evolution while still offering Outlook compatibility.

My office is a mix of Windows and Linux machines running Outlook and Kontact respectively and there isn't a product that allows me to co-ordinate the various calendars, email and address books on both platforms simultaneously.


Evolution support anounced

Mephisto's picture

Hey Alan,

if you scroll down you will see that Evolution support is anounced for Scalix 10 to be released this month. Even better: The Evolution connector will be fully open source.



Not just Zimbra or Scalix

Ben Duncan's picture

Take a look at another alternative to Zimbra and Scalix called @Mail -

A product which offers a complete WebMail, Groupware & Mail-server package for Linux.

The WebMail interface includes an "Outlook" style look for IE and Firefox, including multi-language templates, Outlook Sync support for Calendar/Tasks, Shared address-book, LDAP support, SQL storage for accounts, complete Webadmin interface and more.

For a company evaluating Zimbra or Scalix, be sure to check @Mail since it provides a quality alternative.

atmail/zimbra have limited calendaring/contacts functionality

Anonymous's picture

atmail, unfortunately, doesn't have:
-the ability to view others' calendars
-notification if scheduling others conflicts w/ their calendar items
-the ability to share one's calendar w/ others.

zimbra doesn't allow one to share one's contacts w/ anyone else. that's planned in the 3rd quarter.

no, i don't work for scalix. i'm just in the process of trying to replace exchange w/ a solution that will be better than what users currently have. i haven't tested scalix yet (i'm waiting for them to send me the link to download the trial enterprise edition), otherwise i'd list things you all might find helpful.

more alternatives

Chris Jenkins's picture

atmail works quite nice and is stable. Two other groupware solutions based on ajax webtech with calendar sharing and integrated outlook support are:
- kerio
- zarafa
Both have .com sites with free downloads.

one more thing about atmail

Anonymous's picture

there's no reminder function in the calendar--even though it's running on the mail server.

Poor support from Atmail

Anonymous's picture

This thread is old, but still relevant. I bought Atmail in part based on good reviews here. The product is okay overall, but some features simply don't work and the support is just terrible. Most requests are simply ignored, others they might get back to you in a few weeks telling you to check the permissions. Then they disappear again for weeks at a time. Save your money!

That review was placed by an

Anonymous's picture

That review was placed by an employee on atmail. Atmail is still garbage support and sales wise.

I haven't been following the

Anonymous's picture

I haven't been following the development of Exchange compatible servers or webmail packages, and I was properly impressed by these two. It seems, between Firefox, OpenOffice 2.0 and these Exchange replacements, Microsoft really has something to look out for.

Why only these two?

Art's picture

These are not the only two ajax mail packages. An article of this type is not complete unless you also mention Citadel, a groupware/collaboration server of the same caliber as Zimbra and Scalix, which also contains AJAX functionality. Unlike these two, Citadel is community developed and is a true open source project. It contains AJAX webmail, a calendar and address book, and a slew of features that you won't find in any other package. Please have a look at it.


Anonymous's picture

I used Citadel as a stand-in mail server for several months, just took it down a few weeks ago.

It's a Zimbra-like system (I say that only having seen Zimbra screenshots) that's designed to act like a BBS. (That is where Citadel's roots are...if you're too young you'll have no idea what I mean.)

It was on the buggy side, but functional. I can't, however, see someone replacing an Exchange server with it though unless they have only the lightest of requirements. There were only incremental improvements to the webmail interface vs. squirrelmail. (e.g. searching; however that was one of the least functional features.)

Their support forum (on the Uncensored! Citadel) is quite active and I had all good experiences when I went there for help.

Also, I'd imagine things have changed at least a little bit since I installed.

For the record, I ended up putting money into Apple's 10.5 Server for its (well-)integrated postfix-based mail solution (and everything else...impressive feature set).

For reference:
Home site of the Citadel author(s):
Home site of the Citadel software:
To download the VMware appliance version:


P.S. If you're already an experienced Linux admin and are familiar with configuring Linux mail systems, you may have a much different (better) experience that I did. I'm fairly new at both. It was definitely easy to set up initially, but I didn't have much of a clue where to go when something wasn't working or (even worse) just wasn't working quite right.

More on Scalix

Julie Hanna Farris's picture

Great to see such a thorough review. Thanks for including our product in this roundup and for the feedback. Thought you might be interested in a preview of our latest release, Scalix 10, currently in beta and shipping in February.

- Open source connector for Novell Evolution that provides full email, calendar, contacts and public folder functionality
- Calendar interoperability between Outlook, Evolution and Scalix Web Access
- High availability solution
- Simplified installation
- Advanced web admin/mgt including mailbox size and global password management
- The ability to directly manage Scalix users and groups through Microsoft Management Console (MMC), for customers using Active Directory

A quick word about Scalix's open source strategy, which is based on a hybrid model. The Scalix Server license is not an open source license today, due to 3rd party restrictions. Specifically, Scalix's technology heritage hails from HP OpenMail. We are working to remove these restrictions so that we can open source our server. In new areas of development, like ScalixConnect for Evolution which is licensed under the GPL, we are pursuing open source licensing today.

Thanks again for the opportunity to participate in this discussion.


Update from Zimbra

John Robb's picture

Thank you for the review on our August 2005 Beta 1 Release. We at Zimbra are continuing to move our product forward based on detailed and constructive feedback like what you have provided. I wanted to offer an update on our Beta 3 Update that was just released.

1) We have removed the dependency on iptables and we have made it easier for Zimbra to co-exist with other services running on a server.

2) We have complete support for Firefox and Thunderbird 1.5 and we continue to line up our testing with new versions of these products.

3) We have released the ZCS Connector for Microsoft Outlook and it is included in the 60 day trial version of our Network Edition.

Thank you again for the help in making Zimbra better and we hope to continue to respond to your reviews.


Missing the subject?

ucntcme's picture

While I am glad to see the Citadel and atMail options, I think they were likely left out of the review because they don't appear to fit the theme. The review was not, as I understood it, about webmail clients that use AJAX, but ones *based* on it.

To me that means not using a preponderance of frames and such, but actual AJAX to update portions of the page.

Man WebCit could sure use a better interface ...