domainwidedelegation.comStart free

Use cases → Email operations

Apply a Gmail label to every user's mailbox

Use a delegated service account to apply or update labels across all users, enabling centralised organisation or compliance workflows.

Who it is forIT admins or compliance teams managing email categorisation at scale.
APIsGmail API, Admin SDK
Typical scopesgmail.modify, admin.directory.user.readonly

The problem

Manual labelling is error-prone and slow, and users may ignore or remove required labels. Central enforcement is needed for audits, retention, or sensitive content workflows.

How it works

  1. Enumerate all users with the Admin SDK.
  2. For each user, impersonate and ensure the label exists (creating it if not).
  3. Use the Gmail API to apply or update the label on relevant messages.
  4. Log successes and failures per user and message.

What changes

All users' mailboxes reflect the intended labelling, supporting searches, retention, or reporting requirements without relying on user action.

The trap in this one. Label IDs are per-user, not universal. If you create a label as the service account for one user, that label's ID will be different for another user—even if the visible label name is the same. Scripts that re-use label IDs across users will silently fail to apply labels, and the API does not error helpfully: it just does nothing. Always resolve or create the label for every user and cache per-user label IDs.

Questions people ask

Can I just use the label name when applying labels?

No, the API requires the label ID, not the name, when modifying messages. You must look up or create the label for each user's mailbox.

How fast do label changes propagate for search and filters?

Label changes are usually visible immediately in the UI and for API queries, but large-scale updates can cause temporary lags in search results for some users.

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

Related use cases

Apply consistent signatures across all user mailboxes

Set and update Gmail signatures at scale so every user has the current, compliant footer, regardless of device or client.

Rotate team email delegation without losing track

Switch which team members have delegated access to a shared mailbox, using a service account to automate rotation and audit.

Automate vacation mail delegation with service accounts

Set up and revoke Gmail delegation automatically for out-of-office users, minimising manual admin intervention and delays.