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Use cases → Email operations

Manage Gmail signatures across the entire domain

Update and standardise user signatures via the Gmail API, ensuring compliance and consistency without manual intervention.

Who it is forIT admins responsible for branding, compliance, or legal disclaimers in email signatures.
APIsGmail API
Typical scopesgmail.settings.basic

The problem

Manual signature updates are missed or ignored, leaving old branding, missing legal text, or inconsistent formats across users. Bulk changes for rebranding or regulatory updates are slow and error-prone if not automated.

How it works

  1. Enumerate all active users in the directory.
  2. For each user, impersonate via the delegated service account and call the Gmail API's settings endpoint.
  3. Set the required signature HTML for each user, replacing any existing value.
  4. Periodically verify signatures to detect manual edits or drift.

What changes

All users get the correct signature, with non-compliant or outdated formats overwritten on schedule.

The trap in this one. The Gmail API’s signature update endpoint is eventually consistent. In practice, a successful API response does not guarantee the signature is immediately visible in the user's webmail or mobile app, especially if the user is active during the update. This leads to rare but persistent cases where sent mail uses the old signature for up to several hours after an update — and the API will report the new value if queried. There is no event or webhook for signature propagation, so drift detection must account for this delay.

Watch it explained

“Email Signatures Management for Workspace with Bybrand” — Bybrand on YouTube. Third-party video, included because it covers this ground well. We are not affiliated with the channel.

Questions people ask

Can users still change their signatures manually?

Yes, unless you lock down the Gmail UI with additional controls. Automated resets can overwrite manual edits, but there is always a window where user changes persist.

Does this work for all mailbox types?

The Gmail API only works for users with active Gmail mailboxes. Suspended or non-Gmail accounts will return errors.

Want this built?

This is a pattern we run in production. We will set up the delegation and build this on top of it — $500 per hour, most of it working the same day.

Talk to us Or read the setup guide

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