Thunderbird Mail Client

Extend Thunderbird with Calendar and Address Book synchronisation. The below guide contains information to setup a connection to an owncloud server, but any other CalDAV and CardDAV server would work as well.


  1. If you are porting your Email from Outlook, convert the Outlook PST or OST files to Thunderbird MBOX format with PST Viewer from PST Walker Software. You need a 50 USD home license to convert PST files, and a 75 USD business license to convert OST files.
  2. Copy all files created by PST Walker for one account into Thunderbird\Data\profile\Mail\<your-mail-account-directory>.
  3. Prepare Thunderbird as explained in the next chapter
  4. As of Thunderbird Version 45, the Lightning extension is already installed. This extension provides Calendar functionality.
  5. Click on the Calendar icon on the upper right side of the Thunderbird window to open the Calendar tab. Right-click the default calendar in the left pane, or right-click into the empty space in the left pane to create a new calendar, and enter the path to the DAV server in field Location.
  6. You don't need to worry about the credentials if you already setup the SOGo Connector, it will take care of it.
  7. Note that during the first sync of the calendar, Thunderbird will freeze and become unresponsive, unfortunately there is no progress bar or information displayed. Just wait until Thunderbird becomes responsive again, which indicates the calendar sync has been completed.
  8. If you are using Thunderbird Portable, register it as default mail program in Firefox or Firefox Portable. Select Options –> Applications, then click on mailto and browse to the location of Thunderbird Portable.
  9. Thunderbird to always show remote content of an email.
    1. Navigate to and click on the menu button on the top right of your screen
    2. Within the menu, select “Options” and then make your way to “Advanced” on the far right
    3. On the general tab, click on the “Config editor”
    4. In the window that appears, enter this into the search field (without quotes) “mailnews.message_display.disable_remote_­image”
    5. Double click the result that appears in the box below. The value should change to “False”

Thunderbird on Desktop computers (Windows, Mac, Linux)

  1. Install CategoryManager and Inverse SOGo Connector apps in Thunderbird –> Add-ons
  2. If the SOGo Connector cannot be installed as an app, download the SOGo Connector with a right-click on the button, then install it from file in Thunderbird.
  3. Open Address Book, then click File –> New –>Remote Address Book. Right click on the new address book, disable periodic sync, and enter the following URL to connect, replace “user” with your user name.:
    • Synology DSM: https://your.domain.tld:8443/addressbooks/users/user/addressbook/
    • ownCloud server: https://your.domain.tld/remote.php/dav/addressbooks/users/user/default/
  4. If you have an existing remote address book, change the URL to sync existing contacts. Right click the remote address book and select Synchronize. If you don't, you must initiate the first sync from your mobile device.
  5. Thunderbird will ask for the access credentials to your DAV server, enter them, and select save to Password Manager. This way, you will not need to enter the credentials repeatedly for Address Book and Calendar sync.
  6. After the first manual sync, change the settings of the Address Book to Periodic sync.
  7. Alternatively, install Extension “CardBook”, then you do not need the SOGo Connector.
  8. URLs to connect the Calendar:
    • Synology DSM WebDAV/CalDAV: https://your.domain.tld:5006/homes/users/user/Calendar/<name>. You must create the “Calendar” folder manually, and DSM will add another folder with the name given to the calendar.
    • Synology DSM Calendar App: https://your.domain.tld:5000/caldav/bco/home/. Note: SSL is not available yet for the Calendar App.
    • ownCloud server: https://your.domain.tld/remote.php/dav/calendars/user/default/


Invoke Thunderbird's certificate manager:

cd \PortableApps\ThunderbirdPortable
thunderbird.exe -chrome chrome://pippki/content/certManager.xul