Mozilla Thunderbird is a free, open-source email client that supports modern protocols like CardDAV, making it a great choice for syncing contacts from services such as Google Workspace (formerly G Suite). By enabling CardDAV in Thunderbird, you can view, edit, and manage your Google Contacts directly within your email client.

? Why Use CardDAV with Thunderbird?

CardDAV is an internet standard protocol for synchronizing contact information. Unlike older methods such as CSV imports, CardDAV keeps your contacts automatically updated across devices in real time.

For Google Workspace users, this means:

• Centralized contact management

• Real-time sync between Gmail and Thunderbird

• Consistency across desktop, web, and mobile devices

?️ Step-by-Step: Sync Google Workspace Contacts in Thunderbird

✅ Step 1: Enable CardDAV API in Google Admin (if needed)

If you're an admin of your Google Workspace domain:

1. Visit: https://console.developers.google.com/

2. Enable CardDAV API for your project.

✅ Step 2: Install Thunderbird (if not already)

Download Thunderbird from: https://www.thunderbird.net

✅ Step 3: Add Your Google Account to Thunderbird

1. Go to Account Settings > Account Actions > Add Mail Account

2. Enter your Google Workspace email and password

3. Use OAuth to sign in and grant access

✅ Step 4: Install Add-on (if needed)

Modern Thunderbird supports CardDAV natively through its Address Book, but for enhanced control, you may install:

• CardBook add-on (recommended)

Install from:
Menu > Add-ons and Themes > Search "CardBook"

✅ Step 5: Add Google Workspace Contacts (CardDAV)

In CardBook or Thunderbird Address Book:

1. Click New Address Book

2. Choose Remote > CardDAV

3. Enter:

   • Username: your Google Workspace email

   • URL: https://www.googleapis.com/carddav/v1/principals/YOUR-EMAIL/

   • Use OAuth or App Password (if 2FA is enabled)

4. Complete the setup and sync.

? Security Note:

• If you use 2-Step Verification, create an App Password from your Google Account > Security > App Passwords.

• Always use HTTPS for secure syncing.

? Benefits of CardDAV with Thunderbird:

• Full contact sync with Gmail / Google Contacts

• Edit contacts within Thunderbird

• Lightweight and secure

• Syncs across devices instantly

✅ Conclusion

By using CardDAV in Thunderbird, Google Workspace users can achieve seamless synchronization of contacts. With tools like CardBook, it becomes even more powerful and user-friendly. This setup is ideal for business users, IT professionals, and those who want better control over their contact data in an open-source environment.