I am using the Gmail/Sheets mail merge Apps Script to send a standard email to a set of people outside our organization by fetching the email ID and First name from a google sheet. The standard email also has a pdf attachment of size 4.6 GB. I tested it first by sending emails to my email ID 5 to 6 times (for formatting) and then executed the script for 42 users. The script successfully sent emails to 20 users but stopped after that with an error: "Service invoked too many times for one day: email." We have Google Workspace Business Starter pack for the last 1 year. I reached out to Google support, and they directed me to this space. I also looked at the quota pages, but not sure which of the quota has failed as I have sent only 50 emails using the script. Any help is much appreciated.