Thunderbird does not support the CardDAV standard for address book synchronisation. In order to synchronise, the “SOGo Connector” add-on is necessary.

Technical Requirements:

To synchronise, you will need the following Software:

• Thunderbird
• SOGo Connector
• Download SOGo Connector by right-clicking the download link. Select “Save target as” (or similar). The file will then be downloaded.

Instructions

• To install the add-on, click on “Extras” (in the Thunderbird menu) and then “Add-ons”.
• On the following page, please click the cog symbol (top right) and choose “Install add-on as a file”.
• Select the downloaded add-on in the dialogue box on your hard drive and click “Open”.
• Install the add-on by clicking “Install Now” and restart Thunderbird.

• To set up the synchronisation, in the Thunderbird address book please click on the menu item “File”, then “New”, and then “Remote Address Book”.
• For Connection Names you could enter “Posteo Contacts” or another arbitrary name.
• For the URL, please enter the following, changing john.example to your Posteo username: https://posteo.de:8843/addressbooks/john.example/default

Synchronising between Thunderbird and Posteo happens manually from now on, when you right-click the address book and choose Synchronise. For the first synchronisation, you will be asked for your Posteo address (as the username) and Posteo password. You can then choose to have these details saved.

Problem: If you are continually asked for your Password

Occasionally, your password can not be saved and is then asked for after every restart. In this case, please proceed as follows:

• Download the Thunderbird add-on Saved Password Editor and install it.
• Restart Thunderbird and open Settings. Under “Security”, you will find “Passwords”.
• Click on “Saved Passwords”.
• Go to “New” and enter the following details:
  • Type: Select Note
  • Host: https://posteo.de:8843
  • Note: SabreDAV
  • Username: Your Posteo address in full
  • Password: Your password

• Click OK and restart Thunderbird. You should no longer be asked for your password, and a connection is made with the Posteo server. You will then see a message to say that your data was synchronised.