Closed Bug 134763 Opened 23 years ago Closed 13 years ago

Interact with Microsoft Exchange calendar

Categories

(Calendar :: General, enhancement)

Product:
Calendar
Component:
General
Type:
enhancement
Priority:
Not set
Severity:
normal

Tracking

(Not tracked)

Status:
VERIFIED WONTFIX

People

(Reporter: David.R.Gardiner, Unassigned)

References

Details

(Whiteboard: [parity-outlook][extension fodder]) 

It would be nice to be able to talk to a Microsoft Exchange Server and use the 
calendar information stored there.

I'm not sure how tricky this might be though. Normally, you can talk to 
Exchange via CDO, however I think the variant of CDO that understands calendar 
stuff might be the one that comes with Outlook etc.. This is different from 
the CDO that comes with 2000/XP which i think just can do simple email sending 
etc.

-dave
I'm not giong to be doing this... Sending to nobody@mozilla.org so it can 
find a home!
Assignee: mikep → nobody
Summary: Interact with Microsoft Exchange calendar → [RFE] Interact with Microsoft Exchange calendar
Why not do what evolution does as well.... do webdav to talk to an exchange
server. It currently only seems to work with exchange 2000.
Dupe of Bug 59630?
this bug is pretty important if Mozilla ever wants to be able to "take" over IE
and Outlook.
The calendar that is available now can publish events to a webDAV enabled server.
Assignee: nobody → mikep
I think the best approach for this is to avoid anything other than open,
published standards on the client side.  If someone could write something that
uses the relevant IIS and Exchange SDK's to implement an ical repository over
HTTP and WebDAV, I think that would be the most appropriate answer.  The same
approach could be taken with Notes, Groupwise, etc.

I know of a company that might be willing to pay for the development of this
functionality against Exchange 5.5 and Exchange 2000 servers.
Summary: [RFE] Interact with Microsoft Exchange calendar → Interact with Microsoft Exchange calendar
Well I looked around Exchange 2k and WedDAV and noticed that the collection
http://<EXCHANGE>/exchange/<USER>/Calendar/ contains one item per calendar event
(seems only acked events are there).

Each item contains the mail that Outlook showed (i.e. message/rfc822), which
contains the iCal data. As for the event data themselves, they are stored as
properties of the item, namely urn:schemas:calendar: as the namespace and then
things like dtstart, dtend, etc.

I do not know if this is really something worth interoperate with. I think what
Ximian has done on Evolution and the Exchange Connector is great, but all in all
is it worth it anywhere else than on a Unix box ? I mean when you purchase a CAL
for exchange, the right to use Outlook comes bundled with it so why would people
care to use another client when Outlook is virtually free?

I think the real challenge would be to be able to offer the same functionalities
as Outlook/Exchange as far as meeting planning and that kind of stuff is
concerned by having Mozilla Calendar interact in a clever way with a WebDAV
repository (with Free/Busy information published and public calendar events
readable by all).

Anybody willing to discuss this issue?

If somebody can give me an account on a E2K server with webdav/Outlook web
access enabled I'd be more than happy to look into the E2K SDK stuff. 
> I mean when you purchase a CAL for exchange, the right to 
> use Outlook comes bundled with it so why would people
> care to use another client when Outlook is virtually free?

Agreed. Except that not all of use run Windows. I'm a happy user of Crossover
Office, why? Because I need to run Outlook, not for mail (handled by Mozilla
mail), rather only for the calendar. I'm not the only one around here. So I
definataly see a a great need for this.

On helping with an Exchange account, I cannot since like most enterprises we are
behind a FW, and exchange is not accessable from the outside. However, if it can
help, I will be able to help either in getting the protocol out there (I can
proxy the server on my local box and provide logs) or help in some other ways. 

I really think this bug will help in the general acceptance of the calendar in
the enterprise - what can I do to help?
New contact from mikep@oeone.com to mostafah@oeone.com
Filter on string OttawaMBA to get rid of these messages. 
Sorry for the spam.
Assignee: mikep → mostafah
I stumbled across Rainlendar http://vapaa.dc.inet.fi/~rainy/ which is a small
desktop calendar utility that nicely displays outlook appointments, meeting,
etc.... Have a look at the utility, also available with source code, under GNU
GPL. Perhaps we can reuse come of that code? (posted same comment in bug 59630
by the way).
This is one of two bugs (Bug 59630) that I've found for Exchange calendar
support [should one dupe?].  Comments in the other bug seem to outline the
necessary information for interaction formats. In my personal experience in
trying to get corporate users to switch to Mozilla / Thunderbird, the greatest
boundary has been integration with Exchange Calendaring. I'm confused over the
lack of resources directed toward this issue. If this issue were addressed, it
seems like it would greatly increase the usage of Moz as calendaring / invitees
are so central in many exchange installs. What can be done to increase the
importance and resolution time of this issue?
Hardware: PC → All
I think they're separate issues with overlap. There's calendaring, and then
there's handling the "interesting" way Microsoft creates attachments (TNEF). The
tool "Fentun" can content-handle TNEF messages.
*** Bug 216543 has been marked as a duplicate of this bug. ***
Whiteboard: parity-outlook
FYI: It is also possible to access the calendar of MS-Exchange 2000 via IMAP!
The IMAP folder contains message entries as described in comment 7. So, it is a
alternative method to store/access calendar entries to/of MS-Exchange.
True, but that only works for your own appointments, not shared ones (unless
certain imap folders of others are accessible)

If you use webdav, you get full functionality. There is a sdk for the exchange
webdav as well as some initial implementations in the KDE-PIM.
Has anyone taken this?  I'd like to do it, but I don't know the extend of the 
current WebDAV support in Calendar.  Is there documentation?  Who do I talk to 
about taking this on?
Spencer: Feel free to take this. The webdav support in calendar is very
preliminary ( Once a change is needed to be made, the whole calendar is
downloaded, modified and uploaded again ) so you might need to write something
from scratch.
Ugh, yeah, sounds like I will =D
Anywho, how do I take it?  I don't have the option to re-assign the bug to 
myself.  Do I need to join up somehow to get privs?
Just make sure you come up with gradual changes to the code so that reviewing
them would be easy. A sudden huge change would not be desirable.
Good luck
Assignee: mostafah → spencer
thanks
Status: NEW → ASSIGNED
Thank you for thanking this bug and hope you'll do well!  :-)
Thanks for the encouragement.  I need to get used to the code to find my way 
about, but I'm determined to get this done.  This is the last thing I need to 
cast-off my bonds of Outlook and rejoin the land of the living...
From http://www.novell.com/products/connector

Effective immediately, Evolution Connector for Microsoft Exchange Server
2000/2003 (formerly Ximian Connector) is available under a free, open source
license. Users no longer need a license file to run the software, and source
code has been made public at http://ftp.ximian.com under the terms of the GNU
General Public License (GPL).
I saw that when the press release came out and was going to take a look 
today.  Perhaps I could use the source?  I'll have to look at the license to 
see if that would be possible.

I'd rather get the funcitonality into thunderbird than switch to evolution.
Oh, and thanks for the link! :)
The Evolution plugin I beleve achieves it's Exchange interaction via Webmail. I
would suggest that this is a non-preferrable interaction method to it being done
via the IMAP connection or a *gasp* native Exchange interaction to retrieve the
events.
I don't know much about the Evolution Connector but it use everything from
mails, contacts, calender, etc. if I understood that correctly.  Since most of
the work had been done then it might will be nice for both Mozilla and
Thunderbird to use this somehow and convert all other to this to make it work
with Exchange Server.  Might be a good idea to file a different bug focusing on
this part.
I was planning on using the WEBDAV support, which I believe is what outlook 
uses.

However, if the exchange connector code works well and can easily be 
integrated into thunderbird, then I don't have issue with doing so.
To Comment 11 :
It seems rainlendar uses outlook itself to get the datas. So Mozilla can't reuse
its source code.
I'm not sure this is the right place to be posting this, but I'm an end user
that runs IT for a company running an exchange server.  If you want to get
people who are used to running Outlook and Exchange to come over, you're going
to have to support more than just the calendar.

The IMAP connector works well enough for email, but without Outlook, I cannot
access my contacts, to-do lists or calendar.  It would be great if you could
implement all of those features.  I would never have to purchase a copy of
Outlook for my company again. :)
I think contacts is bug 59631, bug 185067, or bug 238832. I can't find a bug
about to-do lists -- you'll have to report that as a new bug.
I haven't seen any action on this bug since December last year. I would be
interested in helping out, and have recently worked with Exchange WebDAV access.
Is someone (Spencer?) still working on this bug?
Total backburner at the moment, I need to update my source again and have a 
gander.  The last time I looked adding a protocol was not an easy thing, and 
the class heirarchy was cryptic and undocumented.  I'll dive in again, but 
don't let that stop anyone else from working on it if you can get there first.
QA Contact: colint → general
*** Bug 323274 has been marked as a duplicate of this bug. ***
Out of left field:

MDaemon (mail server) has full support for MS Outlook client, and duplicates the server (as seen by Outlook).

So ... Try to define an open std. (with MDaemon's developers) to support this fucntionality in Sunbird / Thunderbird (split against email, calendar, address book as required).

This leaves open 2 paths:
(a.) corporates can migrate to MDaemon (from Exchange), still supporting their Outlook users, as well as FULL / better support for Mozilla.
(b.) we have a 'better' std. and can interest other server-side, and clients to support this.  Particularly unix, linux ..
(c.) MS Outlook adopts this 'NEW' better standard. [no date suggested ;) LOL]

Anyway, just some random thoughts ..
Has any progress been made in this area since the last comment in April '06?  Do either Sunbird or Lightening have any support yet for exchange?  Has anyone been sucessful accessing it exchange data via webdav?
I've been able to read/write data in Exchange 2000/2003 through WebDAV but I do not know anything about coding for Sunbird/Lightning.

Nonetheless I can contribute what I know about it to anyone who is willing to actually write the code for it.
Assignee: spencer → nobody
Status: ASSIGNED → NEW
If Thunderbird is to make any headway in the established Outlook environment, it has to come from the end-users.  IT departments in non-IT companies are more concerned with keeping things running smoothly than trying something completely new.

The calendar functionality is a huge part of that.  For me to be able to stop using Outlook (and I'd love to), Sunbird and Lightning need to be interoperable with an Exchange Server.  This means setting up meetings, viewing when each other is busy, etc.

I'm not a great developer in the languages necessary for this project, but I'd be more than happy to help through testing.
further to comment 39:

We may need to clarify what 'Exchange Server' compatibility should mean.

Yes, we need to be able send / receive meeting notifications.  But, additional software may be required to abstract Exchange content before it can be seen as a (std.) 'published calendar'.

I fully support the need to target Thunderbird & Lightning/Sunbird as the obvious drop in replacement for Outlook.  That should not proclude the replacement of Exchange either.

What we still need to keep as our target is a mix of server and client components (from multiple suppliers) which full inter-operate, and with Mozilla's offerings a strong technology and market leader. 
For people interested in native Exchange support on Linux platforms, OpenChange
has a working MAPI library and just added calendar fetch and
appointment/meeting creation support. It is still alpha, but we are already able to:
- create appointment or meeting
- define start/end date
- set the busy status and the label
- define the title and location

Reminders support and stand-alone application should be added to the repository
within a couple of days.

If someone is interested in adding calendar support to lightning/sunbird using libmapi, we would be more than happy to provide the necessary help. Obviously we do not have the human resources necessary to handle this development on our own, otherwise we would have attempted to provide a preview the same way we did for evolution.

Infos and screenshots available on: http://www.openchange.org
The current code able to create appointments using MAPI is available at the URL below:
http://websvn.openchange.org/filedetails.php?repname=openchange&path=%2Fbranches%2FMAILOOK%2Ftorture%2Fmapi_sendappointment.c
Anyone know if the new Microsoft Interoperability project will eventually include Exchange calendaring?

I don't see anything on their site, at this point

http://www.microsoft.com/interop/
We've proposed a GSoC project [1] for this topic; it's highly appreciated for 0.9, even if based on WebDAV (instead of mapi).

[1] <http://wiki.mozilla.org/Community:SummerOfCode08#Calendar>
Flags: wanted-calendar0.9+
(In reply to comment #44)
> We've proposed a GSoC project [1] for this topic; it's highly appreciated for
> 0.9, even if based on WebDAV (instead of mapi).

The OpenChange project has also proposed a GSoC project [1] for this topic: OpenChange MAPI and Thunderbird integration. We didn't receive applications from students for this project so far.

[1]  <http://wiki.openchange.org/index.php/SoC/Ideas>


Not a priority for 0.9. But we will take patches if a volunteer steps up.
Flags: wanted-calendar0.9+ → wanted-calendar0.9-
(In reply to comment #47)
> does synkolab work with exchange?
> https://addons.mozilla.org/en-US/thunderbird/addon/519
> 

A quick test showed - no, it doesn't :-(
I've begun work on a plugin that will integrate sunbird/lightning into Exchange 2007.  Unfortunately it will not work with previous versions, because it depends on the webservice layer that was introduced in Exchange 2007.

So far the only thing that works is Free/Busy searching, but I plan to add support for directly accessing/viewing/changing calendars in the coming weeks.

I should have a beta release up pretty soon, this is my first mozilla plugin, so I've gotta figure out how to package it up nicely, then it'll be ready to go.
I think it would be better to focus on "real" integration, ie. using the openchange library or something similar to actually speak MAPI.  We don't need another web-scraping solution a la evolution.  It doesn't work when the web interface isn't turned on, and even when it does work it's very slow and ****.

It's up to you guys, of course, but I don't think this would meet most user needs or expectations.
For free/busy searches, each one returns in about 30-50ms, so I wouldn't call it slow, since the information is available as fast as you type the users to invite.  And I certainly wouldn't compare a published SOAP service created for this exact purpose to screen scraping.  I'm not 100% sure, but I believe it's turned on either by default or alongside the webmail plugin, which means it's going to be turned on in most cases.

The big difference between speaking MAPI and web services is that MAPI, while somewhat documented now, is still pretty proprietary and mammoth.  You have to deal with the security protocol, and handle a lot of functionality that really isn't necessary for a calendar integration.  With the web services, you simply make the calls you need for just the information you need.
Sorry for the immediately 2nd post, but I thought of another problem with the MAPI approach... it's changed significantly between 2007 and the previous version of exchange... (hence my evolution will not work with our new servers).  A web service is much less likely to change than the internal protocol used by outlook/exchange.
I would stress that web SERVICES is something other than screen scraping Outlook Web Access! The web services are documented, published and they are a Microsoft supported way of integrating with Exchange. In my opinion the only drawback is that it only comes with Exchange 2007, but that drawback will become less important over time.

See http://msdn.microsoft.com/nl-nl/library/aa565934(en-us,EXCHG.80).aspx
THe MAPI implementation is far from ready, web services implementation can be available long before the MAPI solution. Web services is usually available over the Internet, MAPI is not. If there is a solution for both protocols, you can still use the other if one breaks. I see so many reasons why this implementation is a good idea. I'm looking forward to testing this! Will it be accompanied by an email solution later also?
Instead of griping about this, I'd prefer y'all to rather bring some constructive criticism. You haven't seen the implementation yet and even if it were screen scraping from owa, it would be better than nothing. Using the SOAP layer is far from screen scraping and a good thing (tm).

Of course using openchange would be the best solution, but looking at the requirements, it doesn't seem trivial to do so. An intermediate solution would be nice to satisfy users for now, the openchange solution can then be tackled later on.

Jamon, if you need any help with packaging or have API questions, please feel free to conact me via email (not my bz email, but my mozilla email can be found elsewhere on the web, i.e calendar project about page). My suggestion is to use the mozilla build system, as described at [1].

[1] http://wiki.mozilla.org/Calendar:Creating_an_Extension#Creating_Extensions_with_the_Build_System
Thanks for the links and information Philipp, that helped immensely with the packaging process.

I've got a preliminary version up, please feel free to take a look.  It's a terrible hack job right now, with half of the implementation being a copy of the ICS calendar implementation and just the Free/Busy being implemented for Exchange 2007 Web services.

You can download it from http://www.jamonterrell.com/download/exchangews-0.1.xpi
Jamon, I installed your plugin, and the install went well (after installing Lightning :-) ). I added a new calendar, and put the URL of our OWA client in the Location field (copied from my setup that works in Evolution). But where do I put my user name/mailbox/password? Nothing is retrieved from Exchange, and I don't get any errors.
Some source code related tips follow. Unfortunately I don't have access to an exchange server, so I cannot test anything, but I am sure there are others that will take care.

* You can include the calendar application's calProviderUtils.js and calProviderBase.js, you don't need to package them yourself. The gdata provider does this for example. You might also want to look into calUtils.js it has some nice helpers.

* for the queries, I'd suggest using e4x. this way the source looks a bit cleaner and its also quite nice for parsing responses. Example:

var xsi = new Namespace("xsi", "http://www.w3.org/2001/XMLSchema-instance");
...

var fbQuery =
  <soap:Envelope xmlns:xsi={xsi} ...>
    ...
      <t:Address>{emailAddress}</t:Address>
    ...
  </soap::Envelope>;

Then you can use fbQuery.toXMLString() when passing to the stream loader.

* For parsing the result, e4x is also very helpful. Not sure how the fb response looks like, but a quick google search gave me http://msdn.microsoft.com/en-us/library/aa494212.aspx which the following is based on:

var responseXML;
try {
   responseXML = new XML(str);
} catch (e) {
   return;
}

for each (var fbResponse in responseXML.FreeBusyResponseArray) {
  if (fbResponse.ResponseMessage.@ResponseClass != "Success") {
    continue;
  }
  var view = fbResponse.FreeBusyView;
  for each (var workingPeriod in view.WorkingHours.WorkingPeriodArray) {
    var startTime = workingPeriod.StartTime;
    var endTime = workingPeriod.EndTime;
    // Do something
  }
}

Unfortunately e4x is not really well documented, but you can find examples in the gdata provider and the caldav provider. Other selectors of interest may be:

responseXML..StartTime
 (an XMLList of all StartTime tags under the responseXML)
responseXML.element.(@attribute == "value")
  (only elements with a certain attribute set)


* We have helpers in calProviderUtils for convertFromByteArray(), preparing the http channel. and also to create a calIFreeBusyInterval. This landed recently, but is available in 0.9pre/0.9rc1, and 0.9 is just about to go out the door.

* I realize you want to allow full access using soap, but just so you know: you can add a freebusy provider without needing to implement a calendar provider. To do this, just create a separate component that registers with the freebusy service on startup. If you are creating a calendar provider anyway, you can do as you have been though :-)
I tried testing your plugin, but it says "Requires additional items." What I'm I doing wrong?
Daniel, you need to install the Lightning plugin
Havard, yes of course, I have tried the plugin on two different computers with different lightening versions, one running Linux and one running windows. I'll try contacting  Jamon via email instead, maybe we can discuss this on IRC or something instead, it's not really relevant for the bug.
You should use the Exchange 2007 web service URL instead of the OWA URL.  Also keep in mind that this ONLY works on version 2007 (as that's where the web services were introduced).

The typical url is something like this:  http://exchangeserver.yourcompany.com/EWS/Exchange.asmx

Philipp,
Thanks for the tips, I'll see what all I can take advantage of.

Thanks,
Jamon
Do we want to track issues with that extension/addon here? or is there another place to report them?
Just e-mail me with bugs/issues for now.
Jamon, any updates on the status of your EWS-based plugin? Thanks!
Jamon, unfortunately I can't create new calendar with your extension.. Errors I have:

Error: this.mHooks has no properties

file:///C:/Documents%20and%20Settings/diman/Application%20Data/Thunderbird/Profiles/swc4u4hq.default/extensions/%7B3b1bfcd0-dd03-4142-9bf4-4201724fd5e7%7D/components/calExchangeWSCalendarModule.js -> file:///C:/Documents%20and%20Settings/diman/Application%20Data/Thunderbird/Profiles/swc4u4hq.default/extensions/%7B3b1bfcd0-dd03-4142-9bf4-4201724fd5e7%7D/js/calExchangeWSCalendar.js
Line: 153

Error: [Exception... "'Failure' when calling method: [calICalendarManager::registerCalendar]"  nsresult: "0x80004005 (NS_ERROR_FAILURE)"  location: "JS frame :: chrome://calendar/content/calendarCreation.js :: doCreateCalendar :: line 133"  data: no]

chrome://calendar/content/calendarCreation.js
Line: 133
FWIW, one possibility to interoperate with Microsoft Exchange would be via OpenMapi:

http://www.openmapi.org/
One thing that has troubled me a lot is that there is no freely available test account for a ms exchange server. Can anyone provide a test account for me or possibly someone else interested in developing this?
Did anyone try davmail? Don't have an exchange-server available to test...
http://davmail.sourceforge.net/
(In reply to comment #70)
> Did anyone try davmail? Don't have an exchange-server available to test...
> http://davmail.sourceforge.net/

Argh, I wish I had never read this comment!

1) On RHEL5 I've installed the DavMail binary and thunderbird-lightning-0.90 from EPEL. 

Result: keeps presenting me with tons of reminders from the past; attempts to dismiss them all result in Thunderbird crashing with:

icalerror.c:104: BADARG: Bad argument to function
thunderbird-bin: icalerror.c:106: icalerror_set_errno: Assertion `0' failed.

2) Got an updated libical that is not compiled with "abort on error" (recompiled the 0.43-4 source RPM from Fedora).

Result: Still can not dismiss past reminders due to bug 356002.

3) Unchecked the "read-only" option to work around bug 356002. 

Result: *big* mistake. Dismissing past occurrences of repeating items resulted in the appointments being badly corrupted (e.g. organizer becomes "null" instead of myself) or disappearing altogether!

Needless to say, I completely gave up on this approach.
Hi!

> Argh, I wish I had never read this comment!

Strange, I'm very happy to find out DavMail, finally e-mail and calendaring works with Thunderbird+Lightning against Exchange 2007 "perfectly"! I didn't have zillions of past occurrences so I don't know what it might have caused but with my CentOS 5.3 installation things "just work" based on few days of testing.

PS. Perhaps you could file bugs to davmail.sf.net so those might get fixed - IMHO this the most convincing solution for Exchange 2007 interoperability we have today.

Cheers!
Just recently learned about http://davmail.sf.net/ - works great :-)
http://gitorious.org/lightning-exchange-provider/pages/Home is a provider plugin for Exchange 2007 and 2010 calendars.
I'd actually vote against this bug if posible. Use a well-documented standard protocol for calendar sharing, which lightning already supports, instead of dedicating developers and resources to propietary and closed wannabe-standards
(In reply to Hugo Osvaldo Barrera from comment #78)
> I'd actually vote against this bug if posible. Use a well-documented
> standard protocol for calendar sharing, which lightning already supports,
> instead of dedicating developers and resources to propietary and closed
> wannabe-standards

Even though I generally agree with your arguments, I don't in this specific case. Yes, Microsoft Exchange is proprietary and standards should be preferred. But many users are forced to use Microsoft Exchange but prefer the interface of sunbird or lightning. BTW: sunbird / lightning can be connected with Microsoft Exchange through davmail (http://davmail.sourceforge.net/), but it is not working perfectly in everyday usage.
(In reply to Hugo Osvaldo Barrera from comment #78)
> I'd actually vote against this bug if posible. Use a well-documented
> standard protocol for calendar sharing, which lightning already supports,
> instead of dedicating developers and resources to propietary and closed
> wannabe-standards

Then use Microsoft Exchange Web Services, an open and fully documented API for Exchange access:

http://msdn.microsoft.com/en-us/library/cc535017%28v=EXCHG.80%29.aspx

It's all there, and both DavMail and Evolution already use it. With DavMail you can choose either the old OWA based access method or use EWS. With Evolution you can use the evolution-ews Exchange connector:

http://chenthill.wordpress.com/2011/02/03/lightening-up-evolution-with-exchange-web-services/

evolution-ews is starting to surface on Linux distribution repositories so to get Evolution to work with Exchange one just need to do apt-get/yum and enter account information and see how Exchange addressbook/calendaring/email just work.

It would be great if things would be equally easy with Thunderbird some day. There's a Thunderbird-EWS add-on available but unfortunately it seems that its development hasn't been very active lately:

http://gitorious.org/lightning-exchange-provider/pages/Home

Thanks.
Although the "exchange provider" addon development is inactive, that work is being continued in another addon under active developent:

https://addons.mozilla.org/en-US/thunderbird/addon/exchange-20072010-calendar-/

Also, my own extension ExQuilla which (will) provide(s) an Exchange Web Services account type for Thunderbird for email, contacts, and calendaring will be available Real Soon Now.

As for this bug, if there was a resolution "Won't fix in core, please use an extension" then I would vote for that. Even Google calendar is done currently through an extension.
If the addon works as may be expected, I'd also vote for setting this bug to won't fix... Is it a real provider for Lightning? What are your experiences?
Status: NEW → RESOLVED
Closed: 13 years ago
Resolution: --- → FIXED
Meant to add: closing this bug as user-reviews are positive. If someone disagrees it could be re-opend.
"Resolved->Fixed" is reserved for cases where core code changes were made that changed behavior. That was not done here.

"Resolved->Won't Fix" is more appropriate, but is only supposed to be set by module drivers (of which I am not one). That really is the more appropriate status.
I stand corrected...
Resolution: FIXED → WONTFIX
To make it complete, we usually add this tag so it can be found in case someone wants to create an extension. Maybe not as useful since there are already good extensions for this, but lets be complete :-)
Status: RESOLVED → VERIFIED
Whiteboard: parity-outlook → [parity-outlook][extension fodder]
It feels inappropriate, to put a bug with 80 votes and 7 dupes into status VERIFIED WONTFIX.
regarding: https://addons.mozilla.org/en-US/thunderbird/addon/exchange-20072010-calendar-/

!! This add-on is not compatible with Thunderbird 15 or higher !!!

Please, reopen this bug for Lightning
Anton, the latest version of that add-on works fine on Thunderbird 17.  You're just looking at the old web page, which is no longer maintained.  The current website is http://www.1st-setup.nl/wordpress/?page_id=133
The extension from previous comment is not developed anymore:

(2014-05-08) I do not maintain this add-on anymore. Anyone who would like to take over can use the source at Github for it’s own fork. Thanks to everyone who has supported and helped to get the add-on to it’s current state.

Github repo:
https://github.com/1stsetup/exchangecalendar

Seems to me that the bug should be reopened to have visibility and possibly looking for a developer to integrate EWS support directly into Lightning, instead of relying on 3rd part extensions.
Integrating this directly into Lightning requires a developer to maintain it and the question is if our low volume of contributors can cover this. I've contacted the developer to figure out how we can continue on this. For others reading this bug, note that it not being maintained doesn't necessarily mean that the extension doesn't work on TB31 + Lightning 3.3.
Just a quick update for those who use EWS extension for Lightning. The development has been taken over by Ericsson open source initiative here: https://github.com/Ericsson/exchangecalendar/releases and it's being actively updated.
Another update for those who are following or who have stumbled across this bug:  Ericsson have abandoned the aforementioned EWS add-on.  Development has been taken over by an informal community of developers, and a new stable version was released a few days ago.  The source and binary releases are available at a new GitHub project: https://github.com/ExchangeCalendar/exchangecalendar

Unfortunately, maintenance of the exchangecalendar add-on stalled some time ago and the most recent compatible version is TB 60.9.1. GitHub Issue ExchangeCalendar/exchangecalendar#277 was raised for compatibility update. The consequence is that anyone who relied on the exchangecalendar add-on for mission-critical access to Exchange calendars is stuck on TB 60.9.1.

@:fallen circumstances have changed quite a bit in the intervening time and in hindsight perhaps this bug should not have been verified WONTFIX. I'm not sure what would be achieved by reopening this bug, but it seems more appropriate than filing a new bug. What do you think?

Flags: needinfo?(philipp)

This bug is important history, though I don't see us implementing exchange in core any time soon. Given the exchange ecosystem has its quirks as well I'd be reluctant to make this a core feature due to maintenance concerns, and even if we do it may make sense to add it as a system add-on so the current add-ons format still makes sense.

I've worked on a few provider APIs at https://github.com/thundernest/tb-web-ext-experiments/tree/master/calendar that might make implementing this for TB 78 viable, since a lot of the xpcom specific code can be replaced by more future proof pure javascript.

If someone wants to pick up maintenance I'm happy to help mentor the transition.

Flags: needinfo?(philipp)

(In reply to Armin Fuerst from comment #79)

BTW: sunbird / lightning can be connected with Microsoft Exchange through davmail (http://davmail.sourceforge.net/)

This is a working replacement / workaround. I use it daily.

Someone recently opened a new bug for tracking Exchange support, not just in the Calendar component but generally: Bug 1847846

See Also: → https://bugzilla.mozilla.org/show_bug.cgi?id=1847846
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