FAQ for Thunderbird contact sync with Google
Also see the FAQ for thunderbird contact sync.
What is synchronized?
Thunderbird’s “Personal Address Book” syncs with Google Contacts.
Or you can sync Google Contacts with an addressbook named after your Google email address.
What isn’t synchronized?
Zindus doesn’t sync Thunderbird mailing lists. Lists and the contacts in them are ignored. This feature is on the roadmap.
Contact conversion
Thunderbird and Google don’t support exactly the same set of contact fields.
Here is the list of Google contact fields that map to Thunderbird:
- Full Name
- Primary Email address and Second Email address
- Phone Numbers: Home, Work, Work Fax, Pager, Mobile
- Instant Messaging (AIM)
- Company and Title
- Notes
Postal addresses fields aren’t synced by default because of differences in field formats, but there is a workaround. See the blog post on Google and Thunderbird postal addresses.
Where Google supports multiple values for a contact field, Zindus syncs the first of those with Thunderbird. So if a Google contact has two mobile phone numbers, only the first of those numbers is synced with Thunderbird.
Where a contact on one side of the sync has fields not supported by the other, Zindus tries to preserve the unsupported fields during an update by merging the updated contact into the overwritten contact.
Thunderbird and Google Addressbook differences
No empty contacts
Without ever noticing it, you may find that you have contacts in your Thunderbird address book that don’t have an email address but do have data in some of the other fields, such as FirstName or LastName. If none of the Thunderbird contact fields map to Google contact fields, then as far as Google is concerned, it’s an empty contact, which Google doesn’t allow.
Thunderbird contacts of this sort can’t be synced. Your options are:
- edit the contact to add a Display Name or email address (even a fake one would be ok)
- move the contact into a different Addressbook so that it isn’t synced with Google
It’s also possible for a Google contact with no email address or Display Name to map to a completely empty Thunderbird contact. Contacts of this sort aren’t synced with Thunderbird. If you want such contacts to sync, give them an email address or Display Name.
When rules break
The Thunderbird address book that is synced with Google must comply with Google’s rules. If it doesn’t, the addon will help you fix it, see:
The Google Thunderbird address book: staying in sync
Error Messages
Unauthorized - Token Invalid
The first time the addon authenticates with Google, Google gives the addon an authorization token that the addon sends with subsequent contact requests.
The addon uses this token for months or even years until one day, the token becomes invalid - either because you changed your Google password, or because Google made it invalid (for a reason known only to them).
When that happens, you’ll see an error message:
Unauthorized
In addon versions 0.8.15 and higher, simply sync again. The addon will send your username and password to Google to obtain a new token. Versions 0.8.14 and prior, visit Tools/zindus, Edit the account and select “Test Connection”. This forces the addon to obtain a new authorization token.

Follow on twitter
RSS Feed