Hello @NickD77 ,
You can send as many emails as you want, just be mindful of what your contacts would be expecting. Sending too frequently can result in more unsubscribes and spam reports. Too many unsubscribes and spam reports in a short period of time, or from a single email send, can result in your account needing to be reviewed.
Also keep in mind that plans have a monthly send limit of 10-24 times your total contacts, depending on your plan. Beyond this, an overage fee of $0.002 per email is applied toward next month's bill. So for example, if you have a send limit of 24x and 10,000 total contacts, you can send up to 240,000 total emails before the overage fee of one-fifth of a cent per email would kick in. Make sure to check out this article for a full overview of how the send cap and overage fees work.
See also:
Review FAQ
Billing FAQ
... View more