The Citadel Groupware Server

Microsoft Exchange, Meet Your Replacement
Setting Up E-Mail

First things first, and before you point your mail records to your new Citadel server, you have to tell it what domains to accept e-mail for. I much prefer Citadel's way of handling this as opposed to mucking about in configuration files. To specify the domains for which you're interested in handling e-mail, click on the Advanced menu option, and then the Domain names and Internet e-mail configuration link.

In the resulting page, enter the first domain for which you want to accept mail in the Local host aliases field. Click the Add button, and continue entering more domains as your situation requires (Figure 4).

Figure 4. Internet Configuration

The Local host aliases field is the only setting that absolutely has to be filled out, but you may want to integrate some more-advanced functionality within this screen as well. You can specify the domains to map to the Global Address List (GAL), indicate smart host addresses if your server isn't sending mail directly or point to a SpamAssassin or real-time blackhole list (RBL) host to scrub incoming mail before it's delivered.

That's it. You now can send and receive e-mail out of your Citadel installation.

Setting Up Clients

There's no technical reason why a local client has to be set up at all. WebCit exposes all of the most-used groupware functionality via a Web interface, and users can begin using that immediately to organize their lives. However, local clients do bring some power to the table, and many users won't be satisfied with a Web interface. Therefore, onward we go.

Depending on the needs of your users, a variety of Linux clients can replace Microsoft Outlook. After many setups, we've found that KDE's Kontact is the easiest personal information manager to back onto a Citadel server, so that's what we use here.

Kontact is the KDE Project's all-in-one personal information manager. In a sense, Kontact simply provides a unified interface to access KMail, KOrganizer, KAddressbook and some notes and news components.


Setting up KMail is a rather intuitive process. If you've ever set up a mail client before, you'll be able to set up KMail without issue. As long as you've set up at least one of your Citadel server's IMAP or POP servers, you can set up KMail to use either. Simply plunk in the URL or IP of your Citadel server, your account credentials and be done with it (Figure 5).

Figure 5. Set Up KMail for Citadel


Setting up the calendaring functionality of Kontact is a little more indepth. We've found that the GroupDAV protocol is the easiest and most powerful to set up, so that's what we do here.

One of the few things you need to know is how to construct your GroupDAV URL. Quite simply, your GroupDAV URL is the URL to your Citadel server (including the nonstandard HTTP port if you've told Citadel to listen on a port other than 80) with /groupdav appended to it. In my case, my GroupDAV URL is

To enable KCalendar's groupware functionality, click on the Calendar icon in the left-side pane. At the bottom of the middle pane is a section labeled Calendar. Right-click anywhere in that pane, and select Add. In the resulting window, select the GroupDAV Server option. If you don't see the GroupDAV Server option, it's likely you don't have the kdepim-kresources package installed. Install it, restart Kontact, and you should be good to go.

The Resource Configuration window opens. Enter a name that means something to you in the Name field and your special GroupDAV URL into the URL field. Your user and password credentials are the same ones that you set up when you logged in to Citadel the first time. Click the Update Folder List button, and the bottom Folder Selection pane should populate with Calendar and Tasks radio buttons (Figure 6).

Figure 6. Set up KOrganizer (Kontact) calendar for Citadel.

It seems that clicking the check boxes beside the Calendar and Tasks items would enable those items, but the system is a little buggy. In many cases, two instances of Calendar and Tasks show up, as shown in Figure 6. Further, to enable a Calendar or Tasks item, the only way that seems to work is to right-click each item and select Enable from the context menu.

Once you've enabled the Calendar, you can enter items either within Kontact or within WebCit, and the items synchronize as mail is checked or other server contact occurs (Figure 7).

Figure 7. Kontact in Action



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Anonymous's picture

Just tried out Citadel and I am AMAZED! When they say "Easy Install" they MEAN it! Up and running in about ten minutes. These guys have got it together.

I remember Citadel from its BBS days

Sum Yung Gai's picture

Man, we're going way back now, aren't we? I remember using Citadel and Stonehenge BBS's back in the 1980's. I just got through visiting the current Citadel Web site, and for those like me who remember the original Citadel BBS, prepare to be amazed.

But for this article, I wouldn't have known that Citadel was still alive in *any* form, and I certainly had no idea in the world that it had evolved into a full-blown MS Exchange groupware replacement!

This is something worth downloading and trying out. I used to be a MS Exchange admin before I joined the Free Software movement, and I'm definitely looking forward to trying out this new Citadel. It had a well-deserved good reputation back in the BBS days. I can hardly wait to try out its groupware features of today!

More than just a BBS

c.s.'s picture

Citadel's history as a BBS platform, combined with the fact that the Citadel developers have made an effort to try to change the way you think about groupware, leads some people to believe that the modern Citadel system is really nothing more than an overgrown BBS. But to think that way really does not give due credit to the extremely powerful capabilities of this platform.

Citadel is truly innovative -- it doesn't just try to be a feature-for-feature clone of Microsoft Exchange. The whole concept behind its design is that many of the concepts and style of user interaction that we became familiar with in the BBS world are actually quite useful in a conventional groupware scenario as well.

Using it now

riley's picture

Very true. We moved our mail server (approximately 100 users, previously running Microsoft Exchange) to Citadel, and not only does it perform flawlessly, but it really does change the way you think about groupware. Everyone else is trying to clone "Microsoft's way" but you know what, Microsoft's way is stupid. Citadel's approach is some fresh new thinking.

not only that, the community

Anonymous's picture

not only that, the community is EXTREMELY active.

just joing the mailing list to see.