Tue, 16 Nov 2004

Exchange Replacements

I spent a few hours today researching Exchange replacements. These are products that are designed to replace Microsoft Exchange on the server, but still allow use of Outlook as a client, including the much-beloved calendaring features.
Here's what I came up with.

Date: Tue, 16 Nov 2004 16:24:55 -0800
From: "Christian G. Warden" <cwarden@zerolag.com>
Subject: Exchange replacement analysis - phase 1

There are a handful of products that claim to be Exchange replacements.
They all work in the same manner, using a custom MAPI connector, which
is basically a plug-in for Outlook, to access the server.  Each version
of Outlook has different features so most of these products only work
with certain versions of Outlook.  Because I'm not very familiar with
Outlook, it is difficult for me to tell if these products fully support
the features of Outlook.  We'll need to setup a test environment to
fully evaluate any of these products.

This was previously a closed source server that was open sourced a
couple years ago.  I evaluated it briefly a year or so ago, and it
seemed stable and featureful, but had a bit of a clunky web interface.
It looks like development is pretty active, though.  I haven't evaluated
the Outlook connector, ZideLook[2], which is a commercial product which
costs about $50 per client.  There is no demo of ZideLook available.
ZideLook communicates with OpenGroupware using WebDAV.
OpenGroupware just handles the groupware functionality and integrates
with third-party IMAP servers.

1. http://www.opengroupware.org/en/index.html
2. http://esd.element5.com/product.html?cart=1&productid=517934&languageid=1&nolselection=1¤cies=EUR

SUSE LINUX Openexchange Server[3]
This is a commercial product.  It is distributed a full linux
distribution and cannot be installed on an existing Linux system. (Such
an installation would not be supported at least.)  Pricing is unclear.
The product is supposed to be available for purchase online at
novell.com, but isn't, perhaps because they are currently integrating
the product with Novell's Groupwise.
There is an online demo[4] and the Outlook connector is available for
download[5].  Openexchange is made up of a number of open source
components and comFire, the groupware component, which was licensed from
a company called Netline.  comFire has recently been open sourced by
Netline as Open-Xchange[6], but the Outlook connector is not licensed for
use with Open-Xchange.  The Outlook connector communicates with the
server using WebDAV.  There is a good article about Openexchange[7].

3. http://www.suse.com/us/business/products/openexchange/index.html
4. http://www.suse.com/us/business/products/openexchange/demo.html
5. http://www.suse.com/us/business/products/openexchange/download.html
6. http://mirror.open-xchange.org/ox/EN/product/
7. http://www.linux-magazine.com/issue/48/Suse_Linux_Openexchange_41.pdf

Bynari Insight Server[8] and Insight Connector[9]
I believe Bynari was the first company with an "Exchange replacement on
Linux" product.  Their Outlook connector allows calendars and address
books on an IMAP server.  It claims to require the Insight Server,
though Insight Server uses Cyrus as the IMAP server, so it may work with
a normal Cyrus server.  Insight Server is composed of a number of open
source products such as Postfix, OpenLDAP, and Apache.  Bynari seems to
think most of the value is in the Connector since a 1000 user license
for Insight Connector is $17,000, and a 1000 user license for a bundled
Insight Server and Insight Connector is $18,000.  (Insight Server
without the Connector is also sold for $1,000.)  A demo is available.

8. http://www.bynari.net/index.php?id=1169
9. http://www.bynari.net/index.php?id=7

BILL Workgroup Server[10]/Exchange4Linux[11]
Documentation is kind of spotty on this one.  I don't think it's worth
evaluating except as a last resort.

10. http://www.billworkgroup.org/billworkgroup/home
11. http://www.exchange4linux.com/exchange4linux/Home

None of the Above (IMAP/LDAP/SMTP/WebDAV or FTP)
Depending on the customer's needs, perhaps Outlook in "Internet Mail
Mode" will be sufficient.  IMAP supports shared folders, but I don't
know if it supports setting ACLs.  Outlook also supports LDAP for
address books, but I don't know if supports updating the directory.
Outlook can send meeting requests and responses over email and publish
free/busy time over FTP (and, I think, either WebDAV or HTTP PUT), but I
don't know if this would meet the customer's needs.

I recommend trying out Openexchange first as it seems to be the most
open and widely deployed.


Comments from anyone who has deployed one of these products for use with Outlook would be appreciated.

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