Fix Gmail 2-Way Sync "Insufficient Permission" Error

By Sparkforge Support Team ·Last reviewed May 3, 2026

The "insufficient permission" error means Sparkforge no longer has the Gmail OAuth scopes it needs. Clear cache, reconnect 2-Way Sync, and grant every requested permission.

If Sparkforge returns insufficient permission when sending email, Gmail has stopped trusting the integration. The cause is almost always a revoked, expired, or partially granted set of OAuth scopes.

Why it happens

Password changed — the Gmail password was reset after the integration was set up.
Access revoked — Sparkforge was disconnected from your Google account's third-party app list.
Incomplete scopes — not every permission was checked when you authorized Gmail access.

Step 1: Reconnect 2-Way Sync

Clear your browser cache and cookies, or open an incognito window.
In Sparkforge, go to Settings → Email → 2-Way Sync.
Reconnect the Gmail account.
On the Google consent screen, leave every requested permission checked before clicking Allow.

Step 2: Remove the app and reconnect

If the error persists after a fresh sync, fully revoke the old grant first.

Open Google Account → Security → Third-party apps with account access.
Find the Sparkforge app and click Remove access.
Return to Sparkforge and reconnect Gmail for 2-Way Sync.
Grant every requested permission on the consent screen.

What to keep in mind

Always grant every requested permission. Skipping one breaks send or receive.
Reconnect the integration any time the Gmail password changes.
Make sure the connected mailbox actually has send and receive permissions in Google Workspace.
If your Workspace admin restricts third-party apps, the admin needs to allow Sparkforge before the user can authorize it.

Frequently Asked Questions

What does "insufficient permission" mean?

Gmail is rejecting the send because Sparkforge no longer holds the OAuth scopes it needs. Reconnecting 2-Way Sync with every permission granted resolves it.

Will my password change break the sync?

Yes. Any time the Gmail password is reset, the OAuth grant can be invalidated. Reconnect 2-Way Sync after a password change.

Where do I revoke the old Sparkforge grant?

Google Account, Security, Third-party apps with account access. Remove Sparkforge there before reconnecting in Sparkforge.

What if my Workspace admin blocks third-party apps?

The admin needs to allow Sparkforge in the Google Workspace Admin console before any user in the org can authorize 2-Way Sync.

Do I need to clear cookies?

It is the fastest way to avoid stale Google session data interfering with the new consent flow. Incognito works too.