Exchange Functionality for Linux

Roughly a year ago I
reviewed a mail server for Linux
that features integration with Microsoft's Outlook and offers
calendaring/scheduling options with shared busy/free information.
However, it did not have many features that Outlook offers in
corporate mode, including sending meeting requests to groups of
users who can then reply and delegating rights so secretaries can
manage their bosses agendas on-line. This current review shows a
year's time was enough for Linux solutions to arise that can
compete with Microsoft Exchange and Outlook and offer a lower
price, with all the important features included.Two important issues should be discussed by administrators
who want to get rid of Microsoft Exchange as their groupware
solution, but who also need to offer a equally functional
alternative. Right now, we have Bynari's InsightServer, which can
be used as an Exchange replacement while still using Outlook on
workstations. Still in development, the Kroupware project is moving
fast to produce an equally functional solution that is fully
open-source and free (as in free beer). For the time being, the
Kroupware project works only with Linux (*nix) clients. The
Kroupware project is the product of the German government going
open-source.Bynari InsightServerIn the February 2003 issue of Linux
Journal, Tom Adelstein of Bynari explained how his
company wrote code to replace Exchange, "that troublesome closed
mail and calendar server". I immediately wondered how all this
knowledge works in the real world, where administrators indeed have
to work with what developers think up. So I downloaded all its
binaries and documents and started up VMware. Below, I explain what
to expect when installing Bynari and what is gained when that job
is done.Installing Bynari InsightServerThe first thing you need is a Linux distribution on which to
install the InsightServer. I downloaded the SuSE 8.1 boot.iso as an
install-floppy replacement on CD-ROM. As I use VMware, I connected
the ISO directly to my VM, then started up at IP address
192.168.0.163. Using FTP, I installed SuSE as a minimal sever
system with KDE. From an internal FRP server I downloaded the
InsightServer I downloaded from
www.bynari.net after
subscribing. From the available PDF files, I learned that a number
of ports need to be free before installing the server. So I
disabled Apache and some other stuff to free up several ports:
25(SMTP), 80(HTTP), 110(POP), 143(IMAP), 389(LDAP), 443(HTPS),
636(LDAP over SSL), 993(IMAP/SSL) and 995 (POP/SSL). In SuSE you
can go to YaST-->Modules-->Start/Stop services-->inetd and
enable inetd with no services. That did it for my setup. Then I
unpacked the tar file with

 tar -xvf insightserver-3.5.5.4.tar 
 cd insight* 
./install

A window opens to tell you what ports should be freed, which
it installs in /opt/insight, and how to start and stop the server:
/usr/sbin/insightserver start|stop|restart. You
have to fill in the name of your country you, select a password for
the server manager of the server and enter the domain name of the
server (hanscees.nl in my case). Then you can choose to start the
server and direct the startup to happen automatically when you
restart the computer. How much simpler can it get?Setting Up the ServerAt http://192.168.0.163/insightserver (use your IP address of
course) you can find the administration site. Enter your license
key, and then you can administer the MTA (Exim), add users and set
up your organization in LDAP. You can administer Exim with the a
web-based GUI but also from the command line, with ASCII files.
From here, you can set options regarding mail size, relaying and so
forth.Administering LDAP is the part where you add users and shared
folders. You can import users with LDIF files, and the PDF files
explain how to migrate from an Exchange user group to the
InsightServer. I made a new organization (hanscees.nl), group
(managers) and put myself in place as users Hans-Cees and Hans. As
most of the server consists of open-source components--Apache, Exim
and Cyrus--you can tweak many items with the knowledge from these
projects. The Bynari site has some user forums to give you a hand
with a trial version, if needed.Setting Up OutlookNow for the most important part: setting up Outlook and
discovering what features are available to the users. Can
InsightServer really deliver what my title suggests, a functional
replacement for Exchange? When setting up Outlook I decided not to
follow the easy road and use Windows XP and Outlook for XP; these
are described in the user guides. Instead, I used Windows 98 SE
with Outlook 2000. I chose this because it is a situation many
companies are still in, and a situation I have worked with as a
real-life administrator. I figured if my setup works, the
well-described setup with Windows XP will certainly work fine. So I
began by installing Outlook 2000 and its service packs. Then I
installed the Bynari InsightConnector and the Bynari LDAP client.
The installation was no problem, but the configuration was a bit
difficult to understand. Even though I did not install the
recommended version of Windows and Outlook, I think Bynari could
improve their documentation here. It took me a while to see what
belongs where, mainly because their documentation describes how to
migrate from Exchange, while I was installing from scratch.It turns out that you need to do three things for each client
or profile you use. Before anything else, you need to start up
Outlook and configure it to use workgroup mode. This is important
because Outlook working in internet-mail mode only is not half the
client it can be. As the first task, you must configure an internet
account: use the InsightServer as an SMTP server and fill in None
for the POP server. This SMTP link is your way to send e-mail from
the InsightServer. Second, you need to connect to the InsightServer
with IMAP. To do so, a window opens after you save the POP account
to a .pst folder. Fill in the Insight IP address or name, along
with your account and password. You might use SSL, but it might
cost some serious processor power. If you ever plan to let people
use Outlook over the Internet, it might as well be encrypted. You
can ping the server to see if it works from the configuration
window.Outlook now opens up with all the folders you expect: Inbox,
Calendaring, Tasks, Outbox and so on. If you click on Calendaring,
you need to click on Yes a couple of times so the folder becomes a
sub-folder of the Inbox. The Bynari server has given you rights to
make folders only inside the Inbox folder. The next step is to
configure LDAP. Go to Tool-->Services-->Add, and add a Bynari
LDAP address book. Configure that by filling in the IP address of
the server, a vink by Send messages in RTF text format, your user
name and password, and then click search. In the search window,
fill in your country code, and vink the organization found and all
its sub-containers.Restart Outlook after altering the Services-->Addressing
tab, so your search for users starts in the right container for
your part of the organization. You also might want to give users
their personal contact lists. After restarting Outlook (the client
is still Windows-based, after all), you can tweak some minor
details. On the Bynari tab, consisting of IMAP boxes, Mailbox,
Folders and Synchronize, you can use the folders tab to grant
rights to other users to see, use and/or manage your folders as you
see fit. You can publish your free/busy information for other users
to consult when planning meetings by going to
Tools-->Options-->Calendar-->Options-->Free/Busy
options and filling in information at
ftp://192.168.0.163/freebusy/%NAME%.vcf. You then can find this
information at http://192.168.0.163/freebusy/%NAME%.vcf.Functionality ReportAt this stage you should have a functional client. My little
tests show that you can do now all that you could do with Outlook
and Exchange--send mail, make notes, use the to-do list and so on.
But you also can plan a meeting, send an invitation about it to
users, find users by clicking the To button when making a new mail,
and clicking on Add to select users and groups. You can see whether
people are available by checking the Attendee Availability tab. The
attendees receive your invitation and can accept or decline it, and
their replies are incorporated into your calendar. Better still,
you can give your secretary the rights to do all this for
you.PriceNot unimportant here is the price. Let us compare what one
might spend on software for 50 users.To use Microsoft Exchange 2000:Microsoft Exchange, including 5 client access licenses
(CALs): $1,29945 additional Microsoft Exchange CALs: $3,915Total:
$5,214Windows 2000 server with 25 CALs: $1,79920 additional Windows
2000 CALs: $739Final five CALs: $189Total: $2,727The grand total is $7,941 for the combination of Microsoft
Exchange and Windows 2000 server. A Microsoft Small Business Server
plus CALs is $4,000, but then you cannot grow over 50 users.The Bynari solution will cost you for 50 users:50-person InsightServer family is: $1,095LDAP client for 50
users is about: $350SuSE 8.1: $80Total: $1,525So, in the best case Exchange costs about three times as much
as InsightServer.Overall, I think the Bynari InsightServer with Client has
done what no other company had done yet: they built a server/client
combination for Linux with full Exchange/Outlook functionality that
enables administrators to keep Outlook as the client and get rid of
a Windows server with Exchange. I did not test how many clients
Bynari InsightServer can run on specific hardware, but I expect
that the mainly open-source parts--Cyrus, Apache and Exim--perform
quite well on top of an efficient OS like Linux. A good *nix
administrator should be able to tweak all kinds of things, of
course.Because InsightServer runs on Linux, you can use a number of
journaling filesystems and all kinds of RAID tools, which you will
need if you are building a serious mail server. Already,
InsightServer version 3.xx offers all kinds of new goodies.
Furthermore, it is fit to run in a big enterprise; the underlying
Cyrus LDAP server that holds the post-boxes is scalable. The
InsightServer enterprise version can run on big IBM servers, if you
need that. You also can integrate it with solutions for anti-virus,
anti-spam and so on. It has a basic Squirrel plugin for web
mail.The near future has more in store, as version 4 is scheduled
for release later this month, if not by the time this article
publishes. A distributed setup with different parts of the
organization on different places will be described in that
documentation. A beta release of a web mail server that talks to
Outlook is scheduled for March as well. In the second half of 2003,
an email-client is planned that can use all of Outlook's
functionality but runs on Windows as well as on Linux and other
*nixes and Mac. This last information is quite relevant, as this
will enable administrators to plan a migration path from Windows to
Linux. The money saved by moving part of an organization to Linux
is substantial, because money is saved on both the OS and on using
Outlook (Windows XP plus Outlook costs you $408 per PC).And these days using Linux for non-specialized workers, those
that need only Web, e-mail and text-processing capabilities, is
quite easy. It also opens up the groupware market for businesses
that use only Linux/BSD. Using shared calendars, where you can see
if others are available, is something you do not want to go without
once you have experienced using it. Of course, this client will not
be free, but it certainly will be cheaper than the Microsoft
solutions. The InsightServer product currently on the market and
its near-future versions give administrators a choice to move away
from Microsoft Exchange, where this was a difficult process
previously. Although the Bynari InsightServer will have to prove
itself in the server-room, it certainly is welcome there as far as
I am concerned.Looking Ahead: KroupwareWhile InsightServer is available now, it is not open-source
and it certainly isn't for free. Many things are on my Linux
wishlist, but an all-free (open-source and free as in free beer)
Exchange replacement is certainly one of them, one where Linux
clients also can join the groupware functionality. It seems such a
replacement is in the making in Germany.When searching the web for information on groupware for
Linux, I stumbled across the
Kroupware project.
Kroupware is the project undertaken by three companies contracted
by the Federal Agency of IT- Security for Germany "to provide a
Free Software groupware solution accessible with Windows running
Outlook and GNU/Linux running KDE clients". The project is by no
means finished but currently is in beta; a working version must be
delivered as part of the contract. The project is intertwined with
KDE and uses Cyrus for the LDAP core and Postfix as the MTA. It can
be used with Outlook when a Bynari connector for Exchange is
installed. For me, what puts this project beyond the Bynari
solution is the fact that it is set up with new standards. Bynari
InsightServer, on the other hand, is meant to be used with Outlook
and its closed-source Windows legacy and, later, with its own,
probably closed-source e-mail client.Kroupware contains an e-mail/groupware server and a
Linux-based client. Outlook clients also can join if they use a
Bynari connector, but they will not have total functionality. Other
clients might be developed as well, but they are not included in
the contract for version 1. The important difference is that open
standards are used for exchanging meeting requests and information
and also for exchanging contact information. Contacts are send
between e-mail clients as attachments, vCards, using MIME.
Calendars are stored in LDAP as vCal, a format for calendaring and
scheduling information, now managed by the IMC
(Internet Mail
Consortium).Kroupware has a clear set of specifications that can be found
here.
It includes calendaring, sending meeting requests, checking the
availability of other attendees, and creating personal contact
lists, tasks lists and so on. The big issue at the moment is the
project is not yet finished. Another issue is the project's future
after the completion of version 1 is uncertain. But anyone
following the growth of Linux and open source can see the
potential. An open-source project, providing a much wanted
solution, based on open standards can be a big success. For small
companies and low-budget organizations it may be the only legal
option. Because the standards of Kroupware are open, it will not be
difficult to develop plugins for existing e-mail clients.
Imagen Pegasus Mail
already offers a calendaring and tasklist plugin for Kroupware.
Pegasus is free, has IMAP and LDAP on board and is not plagued by
all kinds of Outlook viruses. Many other e-mail clients can and
will add plugins if the server becomes popular. Linux as a desktop
system also will become much more attractive when full-featured,
Outlook-like functions are on board with the Kroupware Kolab server
as the backend.ConclusionI admit that my enthusiasm is getting the best of me where
the success of Kroupware is concerned; many uncertainties exist as
to how the project will develop. Without a doubt, though, we are
seeing some very positive signs on the Linux skyline. A year ago,
no groupware solution running on Linux existed with which
Outlook-based groupware functions were possible. Now, Linux as an
enterprise solution OS is growing and the Bynari InsightServer,
coupled with Outlook and some plugins, fits nicely into this
picture.ResourcesThe Bynari Web
SiteThe Kroupware Web
SiteThe Internet Mail Consortium
Web SiteSquirrel
Web E-mail