The maximum number of emails that can be sent within a specific period, as defined by an email service provider (ESP) or email platform. These limits can apply to daily, hourly, or monthly email sending volumes and are set to prevent abuse, reduce the risk of spam, and protect the sender's reputation. Email sending limits are crucial for ensuring high deliverability rates and maintaining compliance with anti-spam regulations. They help manage server load, prevent blacklisting, and ensure that email campaigns are executed smoothly.