Linux Based Exchange Replacement

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Exchange server replacement that runs on Linux

I want to build an entirely Linux based network, forget Microsoft for good.

Can anyone suggest free software that will replace the goodies that are included with Exchange and Outlook? Ie: Mailboxes for users, calendars, email, etc. And also a mail client?

Thanks.

From serverfault The Woo

• Take a look at Kolab, Zimbra and eGroupware, all of them attempt to replace Exchange.

  TomTom : And all of them - sady - fail. Basic functionality - yes. Higher functionalty - no. Especially not when you add all the other goodies into the mix.

  dyasny : TomTom: what goodies exactly are you after? We are using Zimbra for thousands of employees

  Janne Pikkarainen : TomTom: You never know what kind of goodies people need. For basic and even for some advanced functionality all the products I mentioned can be very nice. Care to enlighten us with some of the most hottest showstopper bugs Kolab, Zimbra and eGroupware still has?

  sims : I think TomTom is addicted to Exchange.

  TomTom : No, I just happen to have worked with some larger exchange installations.

  MarkM : @dyasny @sims - I think he just likes phrasing his sentences like he is the ultimate authority on everything.

  dyasny : MarkM: don't we all? :)

  dyasny : TomTom: just how large? And what makes you think this particular topicstarter is going to have a setup as large as that?

  coredump : Went from Exchange to Zimbra and had no problems at all, users love it and its pretty easy to manage/backup/troubleshoot since it's just a lot of open source software put together with a smart glue/interface. Around 4k users.

  nedm : We also went from Exchange to Zimbra; much smaller number of users in our case (<100), but it's been wonderful. We evaluated Scalix and Zimbra and finally decided on Zimbra because there was a a supported build for Ubuntu/Debian. One of my favorite features is the Active Directory integration, so users don't need to remember another password.

  pauska : nedm: Thats also one of my favourite features with Exchange..

  nedm : @Erik: True, to put it differently, it was an important feature we didn't want t lose when migrating away from Exchange -- the main feature we *did* want to lose was the expensive license.
  From Janne Pikkarainen

• Despite a nodding acquaintance with the rest of the world, MSExchange has always been modeleld on x400. There are other implementations which based around x400 out there (Lotus Notes, and until it was discontinued, Samsung Contact). However IMHO they are all a complete PITA to manage and should be avoided if at all possible.

  And also a mail client?

  Lets deal with that first. Presumably you mean a client which will provide the users the functionality they have in Outlook. Well, Outlook is probably a sensible starting point. Although Microsoft tend to hide this information away, it will happily talk SMTP, POP, IMAP, LDAP and iCAL.

  Indeed it probably makes a lot of sense to plan an LDAP system (or extending your current provision) to provide address book functionality. If you don't already have a suitable LDAP server, have a look at GOSA. Note that if you have multiple sites, then you should really really have LDAP based mail routing set up.

  Of course, using open standards for server protocols mean that you can choose from lots and lots of user agents - e.g. you could easily add web based clients for mail and calendar, e.g. squirrelmail, Mozilla calendar (but there are many, many more).

  Serverside you need to have a Mail Transport Agent - several years ago I did some research on this and found that Sendmail and Postifx were significantly more effective at sending email compared with Qmail, Exim and others (MS Exchange was bottom of the reliability list). Although Novell's groupwise proved just as reliable.

  I'd recommend using an IMAP server in preference to a POP server. There's lots of good ones out tere scalable up to massive levels. The UoW one usually comes bundled in distributions but you probably need something a bit more sophisticated if you have more than 200 or so users - dovecot or courier maybe.

  There was an open-source project attempting to reimplement mapi as a standard API but AFAIK its not been very active lately.

  In addition to the products mentioned by others, you might want to have a look at sogo

  Your not going to get all the answers here - you're still going to have to do some research and probably try integrating different products - but the maintenance effort will be massively reduced. There's some links below to get you started.

  http://support.microsoft.com/kb/291621 - iCAL stuff

  http://technet.microsoft.com/en-us/library/cc179232%28office.12%29.aspx - LDAP stuff

  http://www.masternewmedia.org/online-meeting-and-appointment-schedulers-comparative-guide/

  http://www.openmapi.org/faq

  http://www.openchange.org/

  http://www.horde.org/

  pjc50 : However if you go this way Outlook doesn't implement shared calendars in the way that Exchange does. This may be a dealbreaker.

  symcbean : @pjc50: yes - and there's lots of other differences between the behaviours of the different implementations of products even when delivering a very well defined requirement (e.g. consider the situation with browsers). But without doing several weeks of analysis I can't tell which of those are relevant.
  From symcbean

• +1 for SOGO. Active development, lot of features, good community.

  From alcy

• The IMHO best alternative hasn't been mentioned in this thread yet. See below. :-)

  I want to build an entirely Linux based network, forget M$ for good.

  Is that a rational decision serving your company's best interests? I'll leave that question to you, but having a negative emotional reaction towards Microsoft isn't a good reason to disregard their products.

  Can anyone suggest free software that will replace the goodies that are included with Exchange and Outlook? Ie: Mailboxes for users, calendars, email, etc. And also a mail client?

  There is no 100% replacement, but Google Apps comes closest, and has most momentum of the Exchange competitors.

  • It is Linux based, in the sense that Google runs on Linux, and it is very easy to get started with.
  • It has good support for open standards, f.x. IMAP over SSL for the Thunderbird & Outlook email clients.
  • Google Apps has excellent device support (iPhone, Android phones, etc) as well. And of course
  • It is a fully managed solution, with built-in spam filtering, antivirus, backups etc, leaving less work for the customer IT staff.
  From Jesper Mortensen

• I didn't see it mentioned so I thought I'd add PostPath. I haven't personally used them but I've heard they offer easy integration with existing Microsoft environments. Something like that might make transitioning a bit easier.

  http://www.cisco.com/web/about/ac49/ac0/ac1/ac259/postpath.html

  -M

  From Mikey B

• i suggest Open eXchange : http://www.open-xchange.com/

  There's a Community edition and a commercial edition.

  From aleroot

• Let's face it, you wont get the full Exchange feature set for free, but for a much better price. Especially the fat client will be a real problem if you want to have all the functions an Outlook / Exchange combination will offer you.

  I had some good experience with Zarafa in the past and even Scalix did the job in small environments (a different story with medium and large installations...).

  From Sascha