Hi,

Those emails come from the calendar sync cron when Google rejects requests (rate limit, expired token, or conflict). Unfortunately, Odoo sends an error email to the user each time.

You have two options to reduce/stop them:

1. Turn off the notification → in Settings › Technical › Scheduled Actions, find Calendar: synchronize user calendars and disable the "Send email on failure" option (or adjust logging level).
2. Fix the root cause → usually it’s an expired Google token. Go to Settings › Integrations › Google Calendar, disconnect and reconnect the account so the sync token is refreshed. You can also reduce sync frequency in the scheduled action.

This way you won’t get spammed, and sync will be more stable.

Hope this helps.