Signature sync add-on

Signature sync for Gmail, a Thunderbird add-on

View project on GitHub

Privacy policy

The Signature sync for Gmail add-on use your Gmail’s data only to update your local signatures.

Which data are accessed

The add-on accesses following data from connected Gmail accounts:

  • e-mail addresses,
  • signatures,
  • OAuth tokens and identifiers.

From Thundebird, the add-on accesses:

  • the list of accounts,
  • signatures.

How data are stored and processed

Nothing is sent outside your local Thunderbird. All your data (signatures, e-mail addresses) and credential details (tokens, identifiers) are stored and processed only locally.

Tokens, e-mail addresses and identifiers can be stored in the local storage separated for the add-on by Thunderbird. Signatures are saved in Thunderbird accounts’ preferences.

External services

There is no other services involved. No telemetry, no cloud storage. The add-on never sends your data outside.

Protection mechanisms

Your sensitive data are protected by using appropriate security mechanisms. All information are stored using the Thunderbird’s built-in mechanisms isolating confidential information from other add-ons; communication with Google APIs occurs exclusively using encrypted HTTPS protocol. The add-on never sends or saves your data outside local Thunderbird instance, and data not needed anymore are immediately deleted.

Limited use

Signature sync for Gmail use and transfer to any other app of information received from Google APIs will adhere to Google API Services User Data Policy, including the Limited Use requirements.

Last update: 2023-11-22


  • 2023-11-22: Added “Protection mechanisms” section.
  • 2021-04-30: Initial version.