Reconnect a disconnected sender

Steps to bring a disconnected sender back online, from checking delegation and scopes to re-authenticating all senders at once.

beginner3 min readUpdated Sat Jul 25 2026 00:00:00 GMT+0000 (Coordinated Universal Time)

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Overview

A sender becomes Disconnected when no uploaded service account can impersonate it. This usually means delegation was changed or removed, a scope is missing, or the service account was deleted. This article walks through bringing it back online.

Before you start

Step-by-step

  1. In the left sidebar, click Accounts, then set the status filter to Disconnected to see affected senders.
  2. In your Google Admin console, confirm that domain-wide delegation still lists your service account's client ID with the correct scopes. See Grant domain-wide delegation and scopes.
  3. Back in Tantra, click Re-authenticate All to re-check every sender against your service accounts.
  4. If only one sender was affected, you can instead re-paste its address in Verify and Add Accounts and click Verify & Add.
  5. Confirm the sender now shows Connected.

What happens next

Re-authenticating re-runs the impersonation check for your senders. Any sender whose delegation and scopes are correct returns to Connected. If it stays disconnected, the problem is on the Google side, usually a missing scope or the wrong client ID.

Notifications

Tantra emails you once a day when senders are found disconnected, so you learn about dropped connections without watching the page. Use that email as a prompt to re-check delegation and re-authenticate.

Common mistakes

  • Re-authenticating before fixing the Google side. If delegation is still wrong, the sender stays disconnected.
  • Deleting and re-adding a sender instead of fixing delegation. Re-authenticating is enough once Google is correct.

Troubleshooting

SymptomCauseFix
Still disconnected after re-authenticatingDelegation missing, wrong client ID, or scopes removedFix the delegation entry in Google, then re-authenticate
Reconnects for calendar but not GmailGmail scopes not grantedAdd gmail.send and gmail.modify, then re-authenticate
The service account was deletedIts key was removed from Tantra or GoogleRe-upload a valid service account and verify again

FAQ

What is the fastest way to reconnect everything?

Fix the delegation in Google if needed, then click Re-authenticate All on the Accounts page.

Why did my sender disconnect on its own?

Something changed on the Google side: delegation was edited, a scope was removed, or the service account was deleted or disabled.

Will Tantra tell me when a sender drops?

Yes. Tantra sends a daily email listing disconnected senders.

Do I lose my sender settings when I reconnect?

No. Reconnecting refreshes the impersonation check. Your per-sender settings remain.

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