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Use cases → Email operations

Update email signatures for many users at once

Push standardised signatures out to large groups by automating the Gmail settings API via domain-wide delegation.

Who it is forIT teams standardising branding or legal footers across hundreds or thousands of accounts.
APIsGmail API
Typical scopesgmail.settings.basic

The problem

Manual signature changes do not scale, and user instructions are ignored or inconsistently followed. Compliance, rebranding or legal changes often require fast, uniform updates that only automation can deliver.

How it works

  1. Fetch the list of target users from the directory or a CSV.
  2. Impersonate each user with a delegated service account.
  3. Call users.settings.sendAs.patch on each account to update the signature.
  4. Log each update and retry failures after a short delay.

What changes

All targeted users receive the updated signature centrally, reducing manual effort and ensuring compliance across the board.

The trap in this one. The Gmail API's signature update is not instantly reflected in the web UI or clients—there is a propagation delay of up to several minutes, especially for large batches. If you re-query immediately to check success, you may get stale data and falsely report a failure. Always allow for this lag and recheck after a suitable delay.

Watch it explained

“UMS Bulk Email Signature Google Workspace Add-on – OAuth Scope Usage & Verification Demo” — UMS Tech Labs on YouTube. Third-party video, included because it covers this ground well. We are not affiliated with the channel.

Questions people ask

Can I set different signatures for different aliases?

Yes, but you must patch the correct sendAs entry for each alias, not just the primary address. Missing this step leaves secondary addresses unchanged.

Will this overwrite user customisations?

Yes, the patch replaces whatever the user had. There is no merge—if users are allowed to edit, their changes will be lost.

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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