Linux Exchange Server – Tips on Choosing the Right Linux Exchange Server

Linux Exchange Servers

Let’s have a detailed look at the Exchange server features at first before diving deep into the fields of servers, clients, and viewers. The following is a brief summary of what we get with an Exchange server:

  • E-mail (sending, receiving, storing)
  • Address Book (Global Address Book)
  • Spam/junk e-mail filtering
  • Calendaring (sharing, publishing free/busy information, public/private categorization)
  • To-do
  • Centralized Management
  • In/out of office access (through clients and web browsers)

All of the competitors have these features, but they differentiate themselves with additional ones. For example E-Groupware offers a project manager, time sheet, wiki, resource management, knowledge base, news admin, polls and shared bookmarks, Citadel offers a mailing list server, built-in instant messaging service, SSL/TLS encryption for all protocols (you can read How to Build a Linux Collaboration Server article for detailed guidance on setting up the Citadel Server), Horde offers customizable portal screen that has applets like weather, quotes etc., Zimbra offers Microsoft Active Directory integration, Kolab offers client-side full support for S/MIME E-mail encryption and and Open X-Change offers document management as additional features.

As we can easily see, the first step in choosing the right Exchange Server for Linux is to make a detailed list of requirements: our business model, what features/functions are required and the like; for example, a transportation company may not need the code tracking function that a software development company requires. Once we have our detailed requirements, then we move on to select our client.

Linux Exchange Mail Client

Choosing the right Linux Exchange mail client depends on two important factors:

  • The compatibility of the client with the chosen server’s features, and
  • The environment that the client will operate: Linux-only environment or mixed environment including Windows servers, Active Directory and/or proprietary protocols.

All of the Exchange Servers for Linux support Outlook connection through plug-ins. If your users are using Outlook for their e-mail and personal information management, then it will be wise to check the Outlook compatibility with the chosen server. If you are operating in a Linux-only environment, then you have to decide on the mail client: Evolution, Kontact or Thunderbird, together with their compatibility.

Linux Mail Client to Connect to Exchange Server

Of course there can be the other side of the coin: your company has a Windows-only system and you want to connect to Microsoft Exchange with your Linux box. Unfortunately you have to know that Linux client compatibility with Exchange is seriously limited. The reason is Microsoft’s proprietary MAPI connection that it uses between the servers and the clients. Only Evolution supports this connection in Linux through Exchange Connector. Don’t get excited yet: the exchange connector is just an interface that brings Outlook Web Access to your computer. In other words, there is virtually no difference between connecting to Web Access with your browser or Evolution client. In my tests, I have frequently experienced crashes when I tried to move messages manually from my Inbox to my mail folders.


We have just scratched the surface with our discussion on Exchange Servers for Linux and Linux Exchange mail clients. All of these Linux collaboration programs except Citadel have commercial support options, which you will need to take into consideration in choosing your server program. Be sure to speak with the companies, their support personnel before choosing your server; you may get valuable information about the current fixes, features nearing implementation etc.. And finally, don’t forget to make extensive tests before deployment.