Gmail sending limit for Google workspace paid account increases to 2000 per day with below conditions:
- your domain has cumulatively paid at least 100$ (early payment will be counted)
- at least 60 days have passed since reaching that payment method.
- the limit resets 2 pm daily – GMT + 7 (midnight pacific time)
+ For apps script: 1500/day (confirmed by google support staff)
+ For gmail: 2000/day
Source: https://support.google.com/a/answer/166852?hl=en#zippy=%2Cconvert-to-a-paid-account%2Climits-increase-for-paid-accounts%2Climits-for-drive-and-groups-with-free-trial-accounts