Issue symptoms
I received an email from Zendesk with the subject You've reached your Google sending limit and shows the error message: Your Zendesk Support account has sent too many notifications in the past 24 hours via Gmail
Resolution
When you enable the Gmail connector, Zendesk uses Gmail’s servers to process all incoming and outgoing mail. This can add up quickly as all notifications from your account are now handled by Gmail. This includes all tickets, knowledge base, and community notifications as well as anything else you are sending through your Zendesk account.
Gmail has a sending limit of 500 emails each day or 2000 emails each day for paid Google apps. When you reach this limit, you will receive this warning message, and Zendesk mail servers will temporarily send notifications instead of Google mail servers.
As a proactive measure, to help prevent you from reaching your rate limit for Google, Zendesk restricts your use at 1500 notifications when you have the Gmail connector enabled, to prevent your Gsuite account from being completely disabled.
To avoid this, use email forwarding instead of the Gmail connector. For more information on setting up forwarding, see the article: How can I switch from the Gmail connector to standard email forwarding?
For any discrepancies or inaccuracies, reach out to Gsuite Support for further guidance on why this limit was reached.