If you're sending mail merge emails from your Gmail account, you're likely aware of the basic limits that Gmail and G Suite set for your accounts. Generally, those limits are 500 emails/day for Gmail accounts and 2,000 emails/day for G Suite accounts. As is often the case though, users find that Gmail limits them below the stated values of 500 and 2,000 per day. For example, a new Gmail account can often only send 10-20 emails in its first 24-hour period. Similarly, a new G Suite account, especially when the domain is a new customer of G Suite, also has limits more restrictive than 2,000 emails/day.