Exchange EWS Provider Add-on for Lightning (Thunderbird/Seamonkey)

(2014-10-21) As you can read I no longer maintain this add-on. But the guys from Ericsson have taken over maintanance. You can get new versions from their github page: https://github.com/Ericsson/exchangecalendar/releases.

I will keep my pages online for the archive.

(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.

!!! The next information is old and outdated !!!

lightningexchangecalendarWelcome on the website with the only add-on for Thunderbird and Seamonkey which will add access to you Exchange calendars, contacts and Global Address List (GAL). It is an add-on for the Lightning Calendering Add-on and will allow you to communicate with an Exchange 2007, 2010 and 2013 server using the Exchange Web Service (EWS) interface.You can access any Calendar, Task or Contacts folder on the EWS server in an easy way. And also manage your “Out of Office” settings.


  • Version 3.2.x for Thunderbird 12 up to 27 (tested up to and with 27).
  • Version 3.1.x for Thunderbird 6 up to 17 (tested up to and with 17).
  • Version 3.0.x for Thunderbird 6 up to 17 (tested up to and with 17).
  • Version 2.x.x for Thunderbird 6 up to 14 (tested up to and with 14).
  • Seamonkey 2.6.1 – 2.20.
  • Lightning add-on
  • This add-on.
  • Access to an Exchange Webservice Server (EWS) with an username, password and/or primarySMTP or email alias.
  • The Exchange Webservice Server of Exchange 2007, 2010 or 2013. Or that from Microsoft Office 365 (see FAQ for howto).

The latest stable version (3.1.3 released 25th of October 2012), which can be newer than on the Mozilla repository, can also be downloaded from this site: [download id=”13″]. If you find problems please report them to the bugzilla. What has changed please see [download id=”14″].

The latest development version (3.2.x) can be downloaded through this link: [download id=”17″]. Because of it’s development nature some new functionality might only work half because it is still in development. Or it is a bug fix which is still in it’s testing phase. If you find problems please report them. See Reporting Bugs. What has changed please see [download id=”18″]. (On GitHUB this is the “master” branch).
Please try this version and turn on offline cache (below calendar settings). When you already use offline cache please turn it first off for the calendar. Restart TB and then turn it on again. It should stay in sync now.

All versions can be downloaded from the download page.

Changed in version 3.2.0-BetaX:

  • Completely new Event Interface. We now use our own which is an extension of the one default in Lightning.
  • New TimeZone function for matching between the Exchange TimeZone and the Lightning TimeZone.
  • Almost complete rewrite of task/todo handling.
  • It will now try to show the Exchange time zone for the start and end times as close as it can match it to the one in Lightning.
  • Added the Exchange SOAP Autodiscovery functionality. This will be used first and when it fails it will fall back to the old POX Autodiscovery.
  • Can follow redirectAddr response from Exchange.
  • Will try Basic authentication as default when available.
  • Fixed problems with opening attachments when having multiple items open.
  • Adjusted reminder configuration to what is possible in Exchange.
  • Address autocompletion for composing emails or adding attendees to calendar event.
  • Showing of icon/image for contact in address book.
  • Added Exchange Task details.
  • Fixed editing Out Of Office messages with HTML editor.
  • New Exchange server version detection.
  • Rich text description editing/viewing including link editing and following.

What can it do:

  • Support Exchange server 2007, 2010 and 2013 (Office365).
  • Sync Calendar, Task/Todo and Contact items from an EWS (Exchange) server.ย  Syncing is done on a user settable poll interval. It will track changes on the server and update the local memory cache.
  • Create, modify and delete calendar events and task/todo items. They will get synced immediately with the EWS server.
  • Contacts are currently read-only.
  • Search the Global Address List (GAL).
  • Use contacts and GAL in address auto completion.
  • During creation of a new calendar you can use the Exchange Autodiscover functionality (when enabled on the Exchange server) to find the right server and mailbox settings. Selecting the right folder is easy with the build-in folder browser.
  • You can access any Calendar, Task or Contacts folder on your EWS server as long as you have the right primarySMTP or alias email address and enough permissions for the used user.
  • Let it poll your inbox for meeting invitation request or cancellations. They will show up in your calendar.
  • Manage how meeting invitations or cancellations are automatically handled (responded to).
  • Add as many calendar objects as you wish and Lightning will allow.
  • Manage “Out of Office”settings for each calendar mailbox.
  • Import ICS files.
  • Export to ICS files. (Experimental: new since 1.8.0a4 not a full calendar yet only local memory cache)
  • Manage and view attachments.
  • Edit event/todo description with rich-text. Colours, fonts, links, etc…
  • User availability (Free/Busy) information.
  • Currently in Dutch (Nederlands), English, French (Franรงais) (Thanks to Dominique Fillon) , Swedish, Japanese and German (Deutsch) (Thanks toย Christian A. Meyer) localizations. When you would like to make a translation for your language please let me know .
  • Can work with Basic, Negotiate and Kerberos authentication. Please see this page for an explanation. No NTLMv1 or NTLMv2 on Linux.

Known issues:

  • When Thunderbird is started or a new Calendar is added it can take some time to load and cache the items from the EWS server. Be patient it will all be loaded. After it is loaded it is fast because it will work with an local temporary memorycache.
  • Because of the previous slowness. When you try to change, add or delete an item during loading this change might take some time to be synced to the EWS server.
  • And those mentioned in the bugzilla.
  • It is not possible to accept or decline assigned tasks. Microsoft does not provide the necessary API calls for this. Even OWA cannot do this. Only outlook.

For questions please send them to Ericsson but first read the FAQ section or have a look at the Forum pages.

If you think of a nice feature or functionality which currently is not available have a look at the feature request page.

If you find a bug in this add-on please report it at https://www.1st-setup.nl/bugzilla/.

319 Responses to Exchange EWS Provider Add-on for Lightning (Thunderbird/Seamonkey)

  1. Paul says:

    Hello! When I initially installed this plugin, it worked great. After restarting Thunderbird, the calendar rejects my password. I know the password is correct because it works for my email on the exchange server. My password is rejected every time now even if I make a new calendar. I’m using version 2.2.2 with Thunderbird 14. Please help. Thanks!

  2. Bryan says:

    I can’t get this working. My exchange email is now working via imap in Thunderbird, but everything I try with your program to get the calender, tasks and contacts to sync fails with so many different errors (depending on what changes I make to try to get this to work) that I don’t know where to start.

    The autodiscover doesn’t work. I get the following when I try that;
    Error during autodiscovery: Fatal XML conversion error. Probably because we did not receive a page with XML. (onLoad)

    Page Not Found

    Page not found

    The page you are


    So I have tried your format of “https://ews.domainname.com/ews/exchange.asmx” in Server URL (and I have tried the owa.domainname.com format as well. I enter my primary email address and my username (I’m assuming this is also my primary email address, but I’ve also tried whatever is left of the “@” and then put in the propert domain name in the Domain Name area). I then get the following multiple error messages when I click on the Check Server and mailbox (FYI I have substituted [domainname] for my proper domain name);

    Error during checking of server and mailbox: HTTP Client error 404: Not found

    Page Not Found

    Page not found

    The page you are looking for might have been removed, had its name changed, or is temporarily unavailable.

    Please try the following:

    If you typed the page address in the Address bar, make sure t

    (Code: -19)

    Then I try the owa address under the Server URL and I get this;

    Error during checking of server and mailbox: Could not connect to specified host:[Exception… “The URI is malformed” nsresult: “0x804b000a (NS_ERROR_MALFORMED_URI)” location: “JS frame :: resource://exchangecalendar/ecExchangeRequest.js :: :: line 235” data: no] (Code: -100)

  3. Paul says:

    This is a follow up to my post from August 18. I uninstalled and reinstalled the extension, and I also tried version 2.2.0. I am not able to delete existing calendars. When I try to add a new calendar, it gets stuck on the discovery process. I wonder if there’s something corrupt that does not get removed when I uninstall.

  4. Paul says:

    This is a follow-up from my previous two posts… I don’t know what was happening, but it’s working fine now.

  5. Tim says:

    Since Thunderbird 15 is officially out now, just wondering if there was any insight into an ETA for a compatible version? Upgrade messages are gonna start popping up for users pretty soon, and sadly this great extension is gonna start breaking for everyone ๐Ÿ™

    Thanks for all the great work in making TB usable in so many Exchange only environments out there.

    • admin says:


      I know. But my time is sparse and the change to do is rather big. So it will take some time.
      Mozilla’s release schedule is faster than I can do.

  6. Klint says:

    The rule is: stick or downgrade to TB 14 until the fix is done ๐Ÿ™‚
    Maybe this statement should be added in an obvious way in the top of this page and on the page on AMO, until the fix is complete, which may take some time as I understood.

    • Steven says:

      Thanks for the great plugin!

      I also experience this problem now I (more or less automatically) upgraded to TB 15…
      How can I savely downgrade (taking care of already upgraded plugins as well)? Could you please advice?


    • PCasteels says:

      I found this after updating to TB 15. How to downgrade and prevent another update?

  7. Klint says:

    Thanks for adding the warning on this page (or was it already here and I did not see it? possible ๐Ÿ™‚ )

    I also have noticed that the AMO page for this addon still show the version 2.2.2 being compliant with TB 6.0 and above, without limit…
    And maybe a similar warning as here?

    Thanks ๐Ÿ™‚

    • admin says:

      Changed the AMO page.
      Please bug Mozilla about their change in the past to not respect the maxVersion settings of add-ons anymore.
      Next week I have time to work on the add-on again.
      Be patient.

  8. steven stern says:

    [Exception… “Component returned failure code: 0x80570015 (NS_ERROR_XPC_CI_RETURNED_FAILURE) [nsIJSCID.createInstance]” nsresult: “0x80570015 (NS_ERROR_XPC_CI_RETURNED_FAILURE)” location: “JS frame :: resource://calendar/modules/calUtils.jsm -> file:///home/sdstern/.thunderbird/wp965fj9.default/extensions/%7Be2fda1a4-762b-4020-b5ad-a41df1933103%7D/calendar-js/calCalendarManager.js :: cmgr_createCalendar :: line 577” data: no]

  9. Klint says:

    to revert back to TB 14.0 while waiting for the addon to be upgraded, read here:

  10. harun says:


    Does anyone know how to make this extension work with the groupware suit called Tine20 calendars? I can normally sync it with my android and other exchance supported platforms.


  11. Matthias says:

    I want to thank you for your work on this great add-on (althouhg it is not working right now). As soon as it is working again, about 20 people in our company will be happy at once!

  12. Roger says:

    Downgrading to TB 14 is much easier using apt. The following link describes one users process. It also worked for me. Although I skipped the “uninstall” step. I just left TB15 installed and let apt do the downgrading. By not uninstalling TB15 you may not need to reinstall your other add-ons / plugins. Your other add-ons may just be disabled

    Here’s the link:

  13. Klint says:

    Hi Michel

    Thanks for your excellent post on bugzilla that clarifies everything to everyone, including moaners I hope ๐Ÿ™‚

    Just noticed something on AMO: the French version of the addon page is in Dutch. Could you switch it to English, please? It will scare French speaking users less, I think.


  14. malevolent says:

    I don’t know what I did, but it’s working for me: Arch Linux, Thunderbird 15, and 2.2.2 version (in german -or dutch-)

  15. Pingback: Add-on working again in Thunderbird 15 | 1st Setup

  16. Klint says:

    Thanks a lot to all those who contributed to the 3.0.0 release ๐Ÿ™‚

  17. David Close says:

    I am using the TB15 Beta and everything seems to be working except it only synced items form 7/26/12 to 8/9/12. Any ideas? When I create a new item, I can see it in my synced calendar on my phone but not in Thunderbird. Am I just not being patient enough?

  18. Ravi Abram says:

    I can see the contacts folder.

    In outlook I have additional address books. How can I add these into the Exchanged contacts?


    • admin says:


      Add a new contact folder. Select the right base folder and folder below base. You can add multiple Exchange contact folders

      • Carlos says:

        Is there any tutorial to add the contacts folder to Thunderbird. I almost tried everything by now. I’m trying to add the new exchange contact folder with the same exchange address I used to setup the calendar, but I keep receiving bad requests from the server.

        Thank you

        • admin says:

          Configuration is almost the same as for a calendar. You need to select the contacts folder and in the latest development version you can even specify if it should search the Global Address List.
          Currently no separate manual yet.

  19. Don Gillespie says:

    I tried to install for Thunderbird 15, but apparently your software is incompatible with Firefox 15, which I also have. Do you or will you have a solution for this problem? I also tried SeaMonkey but the version I have is 2.12, and your software does not work with that either. Any help would be appreciated.

  20. Michael says:

    TB 15.0, with extension 3.0.0-rc3

    When I try to add a new event I get “An error occurred when writing to the calendar Exchange!” When I click on “Details…” it says “Error code: MODIFICATION FAILED”

    I can use TB 14.0 and the 2.x addon with no errors.

  21. Sergey says:

    3.0.0-rc3 works with TB 16
    Thank you
    See only one problem: can’t delete events on MS Exchange
    Can edit but can’t delete

  22. ZehHa says:

    Thanks a lot for the update. Can use the calendar add-on in SeaMonkey 2.12.1 with my work’s exchange account again.

  23. Jonas says:

    Fantastic work! Glad it was fixed so fast – it is people like you who make Linux and Open Source work – thank you !!

  24. Peter van den Biggelaar says:

    In your browser, Right click on the link and select “Save Link As..”
    In Thunderbird: Tools -> Add-ons -> Extensions , click the Tools icon and select “Install Add-on From File”

  25. Pingback: Probleme mit Mozilla Thunderbird 15 โ€บ RRZE: Meldungen und Artikel

  26. Thankful H. User says:

    I can’t tell you how much I love you for this add-on, after years of struggling with being forced to keep Thunderbird and Outlook open simultaneously at the office…
    I have a problem though: Whenever I create a new event in the outlook calendar, it sets a 15mins reminder for it, even though I have “no reminder” as default, and even if I explicitly click the “no reminder” box. I can then edit the event and remove the reminder, but when I switch on Thunderbird the next time, all the reminders come back.
    I’m using 3.0.0.beta2 on Thunderbird 15.0.1, WinXP SP3 and Exchange2010 server (I think).

  27. Leo says:


  28. David brown says:

    Adding free/busy calendars

    We have just recently moved to an external Exchange hosting service, and your plugin here has made life much easier for me (I’d hate to have to use Outlook!).

    Connecting up to my main user’s calendar works perfectly. If I use the Outlook web client to log on as a different user, then give the main user explicit access to the other user’s calendar, then I can also add that other user’s calendar as a read-only calendar in Thunderbird. So far so good!

    But I can’t seem to add calendars for additional users for which I only have default free/busy access. I know I have permission for this level of access – I can add their calendars in the web client (where only free/busy information is shown), and I can see their free/busy information if I try to invite them to an event.

    I’d like to be able to add free/busy calendars without having to explicitly share each of these calendars with each user who wants to see them. Am I doing something wrong here – or is it not possible to do?

    • admin says:

      It should be possible depending on the right they gave you to their calendar. As you say you can see their free/busy info in a web client this should be possible in thunderbird also.
      Just add a new exchange calendar with the same server url and add their primary email address and your own username and password.

      • David brown says:

        That is exactly what I tried. (I’m using version 3.0.0-rc3 of your plugin, if that makes a difference.) But I am getting an error:

        Either you do not have read permission on the selected mailbox or the mailbox is incorrect.
        When the mailbox is corrected you might have permissions to view the Busy/Tentative/OOO user availablity status for its calendar.
        (-208: The specified folder could not be found in the store. (ErrorFolderNotFound))

        I would be perfectly happy with just Free/Busy information for this calendar – that’s all the permission I have. And there is no problem getting that information when inviting attendees to a meeting or event. But it would be nice to have it available in the calendar view as well.

  29. David brown says:

    Will it ever be possible to write new contacts to the Exchange Server contacts list? Importing them as read-only works perfectly, but I need to add them using the Outlook Web Client to get them on the server in the first place.

    Is it possible to access Exchange’s Global Address Lists somehow?

  30. David brown says:

    I don’t think this is actually an issue for this plugin, but people here know a lot more about using Thunderbird with Exchange than most, and can perhaps give me some hints.

    When I “tag” a message in Thunderbird as ToDo, Important, etc., the tag does not seem to be synchronised at the Exchange server. With our old Dovecot imap server, it worked perfectly – tags were stored on the server, and were synchronised for all Thunderbird clients. But with the Exchange server it seems the tag information is not sent, so it is only local to each Thunderbird installation.

  31. Pingback: Version 3.0.0 released for Exchange add-on | 1st Setup

  32. Janne Korkkula says:

    An excellent plugin, big thanks. TB 10 ESR + Lightning 1.2.3 + ECTP 2.2.31 work very well. I’ve had no luck at all with TB 15/16/10ESR and ECTP 3.0.0 beta/rc3/rc4/release. The calendar won’t sync, jobs get stuck. ECTP logs show all events being received, but the calendar displays none, or very few of the newest. A more detailed changelog and changing minor version numbers instead of just build numbers would be welcome.
    Most important is to keep TB 10 ESR supported…

    • admin says:

      My experience is that sometimes starting with a new profile clears a lot of problems. Last time i had on one computer that all items from different calendars showed in one color, transparent, with white text and on another computer all was normal. After i created a new profile on the first computer all was normal as expected.

      I think the profile upgrade between version is sometimes corrupted within thunderbird and the add-on has nothing to do with it.
      The change from 2.x to 3.x is a really big one. About 50% of the code was rewritten to have the add-on working again in TB15 and higher.

  33. me says:

    Excellent add-on ๐Ÿ™‚

  34. Ben de Graaff says:

    Hope there will be a solution for version 16 soon.

    • admin says:

      The latest version of the add-on works in TB 15 and higher. Tested up to 19.0a1. What is not working in TB16?

  35. Ares says:

    Release 3.0.2 cannot connect to exchange from linux/TB14,TB16
    Working fine with 1.8.5 on TB14, TB16 does not accept 1.8.5

  36. Geert Vanmeerbeeck says:

    Vraagje, is het mogelijk om in de Inbox view het icoontje van een meeting invitation te vervangen (zoals in outlook ook het geval): een (mini-) calendertje in plaats van een enveloppe? Hierdoor zijn meeting invitations makkelijker terug te vinden in Inbox…

    • admin says:

      Deze vraag zul je moeten stellen aan de groep die de Lightning add-on beheerd. Als het daarin komt dan is het beschikbaar ook voor andere calender typen.

  37. Hi,

    I have TB14 with addon 2.2.2 and want to upgrade. Before I do that I want to ask if it’s safe to just uninstall 2.2.2, upgrade TB and Lightning and then install 3.1.1 or is there some folder on the profile I should delete or something?


  38. Alexis says:

    Excellent addon, but 3.1.1 needs a lot of memory !!
    for me 1.450.000 K !!!!
    on different pc’s (win7 x64 + win8 x64) with different profiles.

  39. Richard says:

    Unfortunately it doesn’t work with Thunderbird 16.0.1, wich ships with Ubuntu 12.10, anymore..

    • pabouk says:

      I am using the addon in version 3.0.0 since the RC version was released and it worked fine with Thunderbird 15, 16.0.1 and 16.0.2 released with Ubuntu 12.04.1. Now I am using 3.1.3 again without problems. I am not sure what difference in Thunderbird could be between Ubuntu 12.04 and 12.10…

  40. Troy says:

    How can I download version 3.1.1?! The new 3.1.2 is causing many login prompts and nothing is working right, I can’t seem to wget the old version:


    Please help, provide download links to older versions! I am stuck without my Exchange calendar now and need to test the old version working before submitting a bug.

  41. Roalt says:

    I’ve also tried to install 3.1.3 but it keeps complaining about that thunderbird 16.0.1 is not supported. Can a version be made that accepts 16.0.1 ? Thanks.

  42. behn66 says:

    Dear all,

    first thanks for this good piece of work. I am trying to get 3.1.x versions running on Ubuntu 12 with TB 16.0.2.
    Once I am trying to install the pluging, I am getting the message: its not compatible with TB 16.0.2

    Is this expected for 3.1.1, 3.1.2 and 3.1.3 version? Please let me know if I shall add more information to this.

    System 32bit, updated Ubuntu linux 12, TB 16.0.2 and lighning 1.8



  43. behn66 says:

    Please disregard my prio post about not working under ubuntu 12 with TB 16.0.2.

    My stupid fault. Its all doing exclellent fine!
    latest Ubuntu 12, 32bit, TB 16.0.2, 3.1.1 add-on version



  44. Stacey says:


    Just a question. Would it be possible to use a similar method (to this addon) to read and send e-mail to an exchange server?


    • Stacey says:

      I realized this was a really dumb question. because I do get my mail the same was from the server…same address just a different piece of data.


      Nevermind ๐Ÿ™‚

    • admin says:


      Yes the exchange communication part of the add-on can be used to access and send email.
      I al ready started work on an email provider for Thunderbird but did not yet have time to finish this. For email there is no provider framework as there is for calendars.

  45. John says:

    Based on the comments above I installed version 3.1.1 on TBird 16. It works, but it’s soooooo slow. When I open the calendar tab, the calendar is blank and then sloooowly opens, on appointment at a time. It’s really not much use like that. Is there any way to make it more functional and speed it up?

    I don’t think it’s Exchange because the strange thing is that if I add an appointment in Thunderbird it shows up within seconds on my smartphone, so clearly the server is working well, but it sure slows down Thunderbird’s display.

  46. Yury says:

    Wonderful add-on, thank you,
    I am a bit confused about Todos. In Outlook I can mark an email for follow up and assign a due date. Is it supported?
    Oftentimes when an email comes I mark for follow up on my blackberry and deal with it later when I am at my computer. However this doesn’t seem to get pushed through Thunderbird.
    Is it not supported or am I missing a way to configure it?

    • admin says:

      ToDos are on the list. They are different than real tasks and they are also stored in the folder where the email is.
      It is on the wish/todo list for the add-on.

  47. Bernhard says:

    I simply cannot install this addon in Thunderbird. I click on the 3.1.3 link in the post but the file is always downloaded and attempted to be installed in Firefox. I can download the file, but it is downloaded as download.php and I have no idea how to load this into Thunderbird. How do I install this addon in Thunderbird?

    • Bernhard says:

      Ok, I figured it out. I had to drag the “download.php” file from my desktop (where it was downloaded to) into Thunderbird. This made the addon install in Thunderbird.

      But the autodiscovery part doesn’t work. Fortunately ExQuilla for Microsoft Exchange 17 works fine with autodiscover and I could extract the server URL from that. Once it was entered, I had calendar access. ๐Ÿ™‚

  48. ZehHa says:

    After the update to SeaMonkey 2.14, there is an issue with sending E-Mails and viewing the “Sent” folder. SM hangs and spins forever.

    • ZehHa says:

      OK, worked later. Now no error messages. Maybe it just took too long for SeaMonkey to synchronize the folders.

  49. Marc Schoechlin says:

    many thanks for developing and maintaining this plugin – a working exchange integration is a really essential thing for having opensource desktops in commodity cooperations.
    I hope that there are more users which donate money for to get this plugin staying alive…

    Regard Marc

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