An Apps Script email failure can come from missing authorization, the execution identity, a recipient quota, or another product restriction. Diagnose the exact exception before resending messages or changing the account.
Identify who is executing the script
A manual run and an installable trigger can have different effective users. Check the project’s execution record and trigger configuration. The account that opened the spreadsheet or form is not necessarily the account whose email quota a triggered run consumes.
Review the required permissions through the normal authorization flow. A newly added service can require additional consent. Do not place an account password in the script to work around authorization.
Check recipient capacity rather than message count alone
Apps Script has its own daily email-recipient quotas, distinct from Gmail’s ordinary interactive sending limits. Use the current quota table for the relevant account type. Google says these per-user quotas reset twenty-four hours after the first request, rather than promising a universal midnight reset.
MailApp.getRemainingDailyQuota() reports remaining email-recipient capacity for the current execution context. Copy recipients and earlier automated sends matter; a single message sent to many people is not equivalent to one recipient.
Resume only unsent work
Read the exception and inspect the execution history. If a batch failed midway, reconcile what was already sent before retrying. A durable recipient or operation ledger can distinguish completed, failed, and uncertain attempts.
Use a controlled test address after fixing the specific authorization or quota problem. Avoid creating duplicate triggers or moving the same campaign through other accounts to evade limits. If the workflow needs higher sustained capacity, redesign its approved sending process instead of relying on a retry loop to create capacity that is not available.
Browse Gmail & Google Account help
References
- Authorization for Google Services | Apps Script | Google for Developers
- Quotas for Google Services | Apps Script | Google for Developers
- Class MailApp | Apps Script | Google for Developers
Reviewed against the linked official product guidance on November 3, 2026. Features, limits, screen labels, and access can vary by account, platform, region, and organization policy.