Usage Report and Account Limits
The Usage Report allows you to easily keep track of how many emails you've sent over the last month, day and hour. It also displays your sending limits for each time period, along with any overages above your monthly limit. Note that free accounts are not permitted any overage. Attempts to send emails beyond your limits will not be successful. Currently-offered paid accounts are permitted to send in excess of the account's monthly limit, resulting in overage charges as appropriate.
As your sending reputation develops, your hourly and daily limits will grow to be a higher percentage of your overall monthly plan limit - the more you focus on sending great content that your customers love to receive, the faster your reputation will be established.
If you wish to send more emails than your account currently provides, please contact sales to upgrade your account to a higher paid plan.